The Collaborative International Dictionary of English v.0.48:

Master \Mas"ter\ (m[.a]s"t[~e]r), n. [OE. maistre, maister, OF.
   maistre, mestre, F. ma[^i]tre, fr. L. magister, orig. a
   double comparative from the root of magnus great, akin to Gr.
   me`gas. Cf. Maestro, Magister, Magistrate, Magnitude,
   Major, Mister, Mistress, Mickle.]
   1. A male person having another living being so far subject
      to his will, that he can, in the main, control his or its
      actions; -- formerly used with much more extensive
      application than now.
      (a) The employer of a servant.
      (b) The owner of a slave.
      (c) The person to whom an apprentice is articled.
      (d) A sovereign, prince, or feudal noble; a chief, or one
          exercising similar authority.
      (e) The head of a household.
      (f) The male head of a school or college.
      (g) A male teacher.
      (h) The director of a number of persons performing a
          ceremony or sharing a feast.
      (i) The owner of a docile brute, -- especially a dog or
          horse.
      (j) The controller of a familiar spirit or other
          supernatural being.
          [1913 Webster]

   2. One who uses, or controls at will, anything inanimate; as,
      to be master of one's time. --Shak.
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            Master of a hundred thousand drachms. --Addison.
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            We are masters of the sea.            --Jowett
                                                  (Thucyd.).
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   3. One who has attained great skill in the use or application
      of anything; as, a master of oratorical art.
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            Great masters of ridicule.            --Macaulay.
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            No care is taken to improve young men in their own
            language, that they may thoroughly understand and be
            masters of it.                        --Locke.
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   4. A title given by courtesy, now commonly pronounced
      m[i^]ster, except when given to boys; -- sometimes written
      Mister, but usually abbreviated to Mr.
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   5. A young gentleman; a lad, or small boy.
      [1913 Webster]

            Where there are little masters and misses in a
            house, they are impediments to the diversions of the
            servants.                             --Swift.
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   6. (Naut.) The commander of a merchant vessel; -- usually
      called captain. Also, a commissioned officer in the navy
      ranking next above ensign and below lieutenant; formerly,
      an officer on a man-of-war who had immediate charge, under
      the commander, of sailing the vessel.
      [1913 Webster]

   7. A person holding an office of authority among the
      Freemasons, esp. the presiding officer; also, a person
      holding a similar office in other civic societies.
      [1913 Webster]

   Little masters, certain German engravers of the 16th
      century, so called from the extreme smallness of their
      prints.

   Master in chancery, an officer of courts of equity, who
      acts as an assistant to the chancellor or judge, by
      inquiring into various matters referred to him, and
      reporting thereon to the court.

   Master of arts, one who takes the second degree at a
      university; also, the degree or title itself, indicated by
      the abbreviation M. A., or A. M.

   Master of the horse, the third great officer in the British
      court, having the management of the royal stables, etc. In
      ceremonial cavalcades he rides next to the sovereign.

   Master of the rolls, in England, an officer who has charge
      of the rolls and patents that pass the great seal, and of
      the records of the chancery, and acts as assistant judge
      of the court. --Bouvier. --Wharton.

   Past master,
      (a) one who has held the office of master in a lodge of
          Freemasons or in a society similarly organized.
      (b) a person who is unusually expert, skilled, or
          experienced in some art, technique, or profession; --
          usually used with at or of.

   The old masters, distinguished painters who preceded modern
      painters; especially, the celebrated painters of the 16th
      and 17th centuries.

   To be master of one's self, to have entire self-control;
      not to be governed by passion.

   To be one's own master, to be at liberty to act as one
      chooses without dictation from anybody.
      [1913 Webster]

   Note: Master, signifying chief, principal, masterly,
         superior, thoroughly skilled, etc., is often used
         adjectively or in compounds; as, master builder or
         master-builder, master chord or master-chord, master
         mason or master-mason, master workman or
         master-workman, master mechanic, master mind, master
         spirit, master passion, etc.
         [1913 Webster]

               Throughout the city by the master gate.
                                                  --Chaucer.
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   Master joint (Geol.), a quarryman's term for the more
      prominent and extended joints traversing a rock mass.

   Master key, a key adapted to open several locks differing
      somewhat from each other; figuratively, a rule or
      principle of general application in solving difficulties.


   Master lode (Mining), the principal vein of ore.

   Master mariner, an experienced and skilled seaman who is
      certified to be competent to command a merchant vessel.

   Master sinew (Far.), a large sinew that surrounds the hough
      of a horse, and divides it from the bone by a hollow
      place, where the windgalls are usually seated.

   Master singer. See Mastersinger.

   Master stroke, a capital performance; a masterly
      achievement; a consummate action; as, a master stroke of
      policy.

   Master tap (Mech.), a tap for forming the thread in a screw
      cutting die.

   Master touch.
      (a) The touch or skill of a master. --Pope.
      (b) Some part of a performance which exhibits very
          skillful work or treatment. "Some master touches of
          this admirable piece." --Tatler.

   Master work, the most important work accomplished by a
      skilled person, as in architecture, literature, etc.;
      also, a work which shows the skill of a master; a
      masterpiece.

   Master workman, a man specially skilled in any art,
      handicraft, or trade, or who is an overseer, foreman, or
      employer.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Captain \Cap"tain\ (k[a^]p"t[i^]n), n. [OE. capitain, captain,
   OF. capitain, F. capitaine (cf. Sp. capitan, It. capitano),
   LL. capitaneus, capitanus, fr. L. caput the head. See under
   Chief, and cf. Chieftain.]
   1. A head, or chief officer; as:
      (a) The military officer who commands a company, troop, or
          battery, or who has the rank entitling him to do so
          though he may be employed on other service.
      (b) An officer in the United States navy, next above a
          commander and below a commodore, and ranking with a
          colonel in the army.
      (c) By courtesy, an officer actually commanding a vessel,
          although not having the rank of captain.
      (d) The master or commanding officer of a merchant vessel.
      (e) One in charge of a portion of a ship's company; as, a
          captain of a top, captain of a gun, etc.
      (f) The foreman of a body of workmen.
      (g) A person having authority over others acting in
          concert; as, the captain of a boat's crew; the captain
          of a football team.
          [1913 Webster]

                A trainband captain eke was he.   --Cowper.
          [1913 Webster]

                The Rhodian captain, relying on . . . the
                lightness of his vessel, passed, in open day,
                through all the guards.           --Arbuthnot.
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   2. A military leader; a warrior.
      [1913 Webster]

            Foremost captain of his time.         --Tennyson.
      [1913 Webster]

   Captain general.
      (a) The commander in chief of an army or armies, or of the
          militia.
      (b) The Spanish governor of Cuba and its dependent
          islands.

   Captain lieutenant, a lieutenant with the rank and duties
      of captain but with a lieutenant's pay, -- as in the first
      company of an English regiment.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Captain \Cap"tain\, v. t.
   To act as captain of; to lead. [R.]
   [1913 Webster]

         Men who captained or accompanied the exodus from
         existing forms. --Lowell.
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The Collaborative International Dictionary of English v.0.48:

Captain \Cap"tain\, a.
   Chief; superior. [R.]
   [1913 Webster]

         captain jewes in the carcanet.           --Shak.
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WordNet (r) 3.0 (2006):

captain
    n 1: an officer holding a rank below a major but above a
         lieutenant
    2: the naval officer in command of a military ship [syn:
       captain, skipper]
    3: a policeman in charge of a precinct [syn: captain, police
       captain, police chief]
    4: an officer who is licensed to command a merchant ship [syn:
       master, captain, sea captain, skipper]
    5: the leader of a group of people; "a captain of industry"
       [syn: captain, chieftain]
    6: the pilot in charge of an airship [syn: captain, senior
       pilot]
    7: a dining-room attendant who is in charge of the waiters and
       the seating of customers [syn: captain, headwaiter,
       maitre d'hotel, maitre d']
    v 1: be the captain of a sports team

Moby Thesaurus II by Grady Ward, 1.0:

192 Moby Thesaurus words for "captain":
   ADC, CO, G-man, MP, OD, administer, administrate, admiral,
   aeronaut, aeroplaner, aeroplanist, aide, aide-de-camp, air pilot,
   airplanist, astronaut, aviator, bailiff, barnstormer, be master,
   be responsible for, beadle, beagle, birdman, boatswain,
   bound bailiff, brigadier, brigadier general, call the signals,
   carry on, castellan, catchpole, chair, chatelain, chatelaine,
   chicken colonel, chief engineer, chief mate, chief of police,
   chief of staff, chief petty officer, cloud seeder, colonel,
   command, commandant, commander, commander in chief,
   commanding officer, commercial pilot, commissioned officer,
   commissioner, commodore, company officer, conduct, constable,
   control, copilot, crop-duster, deck officer, deputy,
   deputy sheriff, detective, direct, director, discipline, engineer,
   ensign, exec, executive, executive officer, fed, federal,
   field marshal, field officer, first lieutenant, five-star general,
   fleet admiral, flic, flier, four-star general, gendarme, general,
   general officer, generalissimo, govern, government man, governor,
   handle, head, head up, inspector, instructor, intendant, jemadar,
   jet jockey, junior officer, lead, lead on, licensed pilot, lictor,
   lieutenant, lieutenant colonel, lieutenant commander,
   lieutenant general, lieutenant junior grade, mace-bearer, major,
   major general, make the rules, manage, manager, maneuver,
   manipulate, marechal, marshal, master, mastermind, mate,
   mounted policeman, narc, naval officer, navarch,
   navigating officer, navigator, officer, one-star general, order,
   orderly officer, patrolman, patron, peace officer, petty officer,
   pilot, pipes, police captain, police commissioner,
   police constable, police inspector, police matron, police officer,
   police sergeant, policeman, policewoman, portreeve, prescribe,
   preside over, pull the strings, quarterback, quartermaster,
   rainmaker, rear admiral, reeve, regulate, risaldar, roundsman,
   ruler, run, sailing master, second mate, senior officer, sergeant,
   sergeant at arms, shavetail, sheriff, shipmaster, sirdar, skipper,
   staff officer, stand over, stunt flier, stunt man, subahdar,
   subaltern, sublieutenant, superintendent, supervise, take command,
   take the lead, test pilot, the Old Man, the brass,
   three-star general, tipstaff, tipstaves, top brass, trooper,
   two-star general, vice admiral, warrant officer, watch officer,
   wield authority, wingman



Easton's 1897 Bible Dictionary:

Captain
   (1.) Heb. sar (1 Sam. 22:2; 2 Sam. 23:19). Rendered "chief,"
   Gen. 40:2; 41:9; rendered also "prince," Dan. 1:7; "ruler,"
   Judg. 9:30; "governor,' 1 Kings 22:26. This same Hebrew word
   denotes a military captain (Ex. 18:21; 2 Kings 1:9; Deut. 1:15;
   1 Sam. 18:13, etc.), the "captain of the body-guard" (Gen.
   37:36; 39:1; 41:10; Jer. 40:1), or, as the word may be rendered,
   "chief of the executioners" (marg.). The officers of the king's
   body-guard frequently acted as executioners. Nebuzar-adan (Jer.
   39:13) and Arioch (Dan. 2:14) held this office in Babylon.

     The "captain of the guard" mentioned in Acts 28:16 was the
   Praetorian prefect, the commander of the Praetorian troops.

     (2.) Another word (Heb. katsin) so translated denotes
   sometimes a military (Josh. 10:24; Judg. 11:6, 11; Isa. 22:3
   "rulers;" Dan. 11:18) and sometimes a civil command, a judge,
   magistrate, Arab. _kady_, (Isa. 1:10; 3:6; Micah 3:1, 9).

     (3.) It is also the rendering of a Hebrew word (shalish)
   meaning "a third man," or "one of three." The LXX. render in
   plural by _tristatai_; i.e., "soldiers fighting from chariots,"
   so called because each war-chariot contained three men, one of
   whom acted as charioteer while the other two fought (Ex. 14:7;
   15:4; 1 Kings 9:22; comp. 2 Kings 9:25). This word is used also
   to denote the king's body-guard (2 Kings 10:25; 1 Chr. 12:18; 2
   Chr. 11:11) or aides-de-camp.

     (4.) The "captain of the temple" mentioned in Acts 4:1 and
   5:24 was not a military officer, but superintendent of the guard
   of priests and Levites who kept watch in the temple by night.
   (Comp. "the ruler of the house of God," 1 Chr. 9:11; 2 Chr.
   31:13; Neh. 11:11.)

     (5.) The Captain of our salvation is a name given to our Lord
   (Heb. 2:10), because he is the author and source of our
   salvation, the head of his people, whom he is conducting to
   glory. The "captain of the Lord's host" (Josh. 5:14, 15) is the
   name given to that mysterious person who manifested himself to
   Abraham (Gen. 12:7), and to Moses in the bush (Ex. 3:2, 6, etc.)
   the Angel of the covenant. (See ANGEL.)


Bouvier's Law Dictionary, Revised 6th Ed (1856):

CAPTAIN or SEA CAPTAIN, mar. law. The name given to the master or commander
of a vessel. He is known in this country very generally by the name of
master. (q.v.) He is also frequently denominated patron in foreign laws and
books.
     2. The captains in the navy of the United States, are officers
appointed by government. Those who are employed in the mercantile service,
have not strictly an official character. They are appointed or employed by
the owners on the vessels they command.
     3. It is proposed to consider the duty  of the latter. Towards the
owner of the vessel he is bound by his personal attention and care, to take
all the necessary precautions for her safety; to, proceed on the voyage in
which such vessel may be engaged, and to obey faithfully his instructions;
and by all means in his power to promote the interest of his owner. But he
is not required to violate good faith, nor employ fraud even with an enemy.
3 Cranch, 242.
     4. Towards others, it is the policy of the law to hold him responsible
for all losses or damages that may happen to the goods committed to his
charge; whether they arise from negligence, ignorance, or willful misconduct
of himself or his mariners, or any other person on board the ship. As soon,
therefore, as goods are put on board, they are in the master's charge, and
he is bound to deliver them again in the same state in which they were
shipped, and he is answerable for all losses or damages they may sustain,
unless it proceed from an inherent defect in the article, or from some
accident or misfortune which could not be prevented.
     5. It may be laid down as a general rule, that the captain is
responsible when any loss occurs in consequence of his doing what he ought
not to do, unless he was forced by the act of God,. the enemies of the
United States, or the perils of the sea.1 Marsh. Ins. 241; Pard. n. 658.
     6. The rights of the captain are, to choose his crew as he is
responsible for their acts, this seems but just, but a reasonable deference
to the rights of the owner require that he should be consulted, as he, as
well as the captain, is responsible for the acts of the crew. On board, the
captain is invested with almost arbitrary power over the crew, being
responsible for the abuse of his authority. Ab. on Shipp. 162. He may repair
the ship, and, if he is not in funds to pay the expenses of such repairs, he
may borrow money, when abroad, on the credit of his owners or of the ship.
Abb. on Sh. 127-8. In such cases, although contracting within the ordinary
scope of his powers and duties, he is generally responsible as well as the
owner. This is the established rule of the maritime law, introduced in favor
of commerce it has been recognized and adopted by the commercial nations of,
Europe, and is derived from the civil or Roman law. Abbott, Ship. 90; Story,
Ag. Sec. 116 to 123, Sec. 294; Paley, Ag. by Lloyd, 244; 1 Liverm. Ag. 70;
Poth. Ob. n. 82; Ersk. Inst. 3, 3, 43; Dig. 4, 9, 1; Poth. Pand. lib. 14,
tit. 1; 3 Summ. R. 228. See Bell's Com. 505, 6th ed; Bouv. Inst. Index, h.t.