The Collaborative International Dictionary of English v.0.48:

Second \Sec"ond\, v. t. [imp. & p. p. Seconded; p. pr. & vb.
   n. Seconding.] [Cf. F. seconder, L. secundare, from
   secundus. See Second, a.]
   1. To follow in the next place; to succeed; to alternate.
      [R.]
      [1913 Webster]

            In the method of nature, a low valley is immediately
            seconded with an ambitious hill.      --Fuller.
      [1913 Webster]

            Sin is seconded with sin.             --South.
      [1913 Webster]

   2. To follow or attend for the purpose of assisting; to
      support; to back; to act as the second of; to assist; to
      forward; to encourage.
      [1913 Webster]

            We have supplies to second our attempt. --Shak.
      [1913 Webster]

            In human works though labored on with pain,
            A thousand movements scarce one purpose gain;
            In God's, one single can its end produce,
            Yet serves to second too some other use. --Pope.
      [1913 Webster]

   3. Specifically, (Parliamentary Procedure) to support, as a
      motion[6] or proposal, by adding one's voice to that of
      the mover or proposer.
      [1913 Webster]

   Note: Under common parliamentary rules used by many
         organizations, especially legislative bodies, a motion
         must be seconded in order to come properly before the
         deliberative body for discussion. Any motion[6] for
         which there is no second[8] dies for lack thereof.
         [PJC]

The Collaborative International Dictionary of English v.0.48:

Second \Sec"ond\, a. [F., fr. L. secundus second, properly,
   following, fr. sequi to follow. See Sue to follow, and cf.
   Secund.]
   1. Immediately following the first; next to the first in
      order of place or time; hence, occurring again; another;
      other.
      [1913 Webster]

            And he slept and dreamed the second time. --Gen.
                                                  xli. 5.
      [1913 Webster]

   2. Next to the first in value, power, excellence, dignity, or
      rank; secondary; subordinate; inferior.
      [1913 Webster]

            May the day when we become the second people upon
            earth . . . be the day of our utter extirpation.
                                                  --Landor.
      [1913 Webster]

   3. Being of the same kind as another that has preceded;
      another, like a prototype; as, a second Cato; a second
      Troy; a second deluge.
      [1913 Webster]

            A Daniel, still say I, a second Daniel! --Shak.
      [1913 Webster]

   Second Adventist. See Adventist.

   Second cousin, the child of a cousin.

   Second-cut file. See under File.

   Second distance (Art), that part of a picture between the
      foreground and the background; -- called also middle
      ground, or middle distance. [R.]

   Second estate (Eng.), the House of Peers.

   Second girl, a female house-servant who does the lighter
      work, as chamber work or waiting on table.

   Second intention. See under Intention.

   Second story, Second floor, in America, the second range
      of rooms from the street level. This, in England, is
      called the first floor, the one beneath being the
      ground floor.

   Second thought or Second thoughts, consideration of a
      matter following a first impulse or impression;
      reconsideration.
      [1913 Webster]

            On second thoughts, gentlemen, I don't wish you had
            known him.                            --Dickens.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Second \Sec"ond\, n.
   1. One who, or that which, follows, or comes after; one next
      and inferior in place, time, rank, importance, excellence,
      or power.
      [1913 Webster]

            Man
            An angel's second, nor his second long. --Young.
      [1913 Webster]

   2. One who follows or attends another for his support and
      aid; a backer; an assistant; specifically, one who acts as
      another's aid in a duel.
      [1913 Webster]

            Being sure enough of seconds after the first onset.
                                                  --Sir H.
                                                  Wotton.
      [1913 Webster]

   3. Aid; assistance; help. [Obs.]
      [1913 Webster]

            Give second, and my love
            Is everlasting thine.                 --J. Fletcher.
      [1913 Webster]

   4. pl. An article of merchandise of a grade inferior to the
      best; esp., a coarse or inferior kind of flour.
      [1913 Webster]

   5. [F. seconde. See Second, a.] The sixtieth part of a
      minute of time or of a minute of space, that is, the
      second regular subdivision of the degree; as, sound moves
      about 1,140 English feet in a second; five minutes and ten
      seconds north of this place.
      [1913 Webster]

   6. In the duodecimal system of mensuration, the twelfth part
      of an inch or prime; a line. See Inch, and Prime, n.,
      8.
      [1913 Webster]

   7. (Mus.)
      (a) The interval between any tone and the tone which is
          represented on the degree of the staff next above it.
      (b) The second part in a concerted piece; -- often
          popularly applied to the alto.
          [1913 Webster]

   8. (Parliamentary Procedure) A motion in support of another
      motion which has been moved in a deliberative body; a
      motion without a second dies without discussion.
      [PJC]

   Second hand, the hand which marks the seconds on the dial
      of a watch or a clock.
      [1913 Webster]

WordNet (r) 3.0 (2006):

second
    adv 1: in the second place; "second, we must consider the
           economy" [syn: second, secondly]
    adj 1: coming next after the first in position in space or time
           or degree or magnitude [syn: second, 2nd, 2d]
    2: a part or voice or instrument or orchestra section lower in
       pitch than or subordinate to the first; "second flute"; "the
       second violins" [ant: first]
    n 1: 1/60 of a minute; the basic unit of time adopted under the
         Systeme International d'Unites [syn: second, sec, s]
    2: an indefinitely short time; "wait just a moment"; "in a mo";
       "it only takes a minute"; "in just a bit" [syn: moment,
       mo, minute, second, bit]
    3: the fielding position of the player on a baseball team who is
       stationed near the second of the bases in the infield [syn:
       second base, second]
    4: a particular point in time; "the moment he arrived the party
       began" [syn: moment, minute, second, instant]
    5: following the first in an ordering or series; "he came in a
       close second"
    6: a 60th part of a minute of arc; "the treasure is 2 minutes
       and 45 seconds south of here" [syn: second, arcsecond]
    7: the official attendant of a contestant in a duel or boxing
       match
    8: a speech seconding a motion; "do I hear a second?" [syn:
       second, secondment, endorsement, indorsement]
    9: the gear that has the second lowest forward gear ratio in the
       gear box of a motor vehicle; "he had to shift down into
       second to make the hill" [syn: second gear, second]
    10: merchandise that has imperfections; usually sold at a
        reduced price without the brand name [syn: irregular,
        second]
    v 1: give support or one's approval to; "I'll second that
         motion"; "I can't back this plan"; "endorse a new project"
         [syn: second, back, endorse, indorse]
    2: transfer an employee to a different, temporary assignment;
       "The officer was seconded for duty overseas"

Moby Thesaurus II by Grady Ward, 1.0:

282 Moby Thesaurus words for "second":
   B, Janus-like, Maecenas, OK, abettor, abundant year, academic year,
   accept, accredit, acolyte, adjutant, admirer, advance, advocate,
   affirm, aficionado, agent, aid, aide, aide-de-camp, aider,
   alternate, alternative, ambidextrous, amen, angel, annum, another,
   apologist, approve, approve of, assign, assist, assistant,
   attendant, authenticate, authorize, autograph, auxiliary, back,
   back up, backer, best man, bifacial, bifold, biform, bilateral,
   binary, binate, biparous, bissextile year, bivalent, breath, buff,
   calendar month, calendar year, century, certify, champion,
   coadjutant, coadjutor, coadjutress, coadjutrix, common year,
   conduplicate, confirm, consecutive intervals, cosign, countersign,
   coup, crack, day, decade, decennary, decennium, defective,
   defective year, defender, degree, dependence, deputy, diapason,
   diatessaron, diatonic interval, diatonic semitone, disomatous,
   double, double-faced, dual, duple, duplex, duplicate, encourage,
   encourager, endorse, endorser, enharmonic diesis,
   enharmonic interval, espouse, executive officer, exponent, fan,
   favor, favorer, fifth, fiscal year, flash, following, fortnight,
   fourth, friend at court, geminate, geminated, get behind,
   get in behind, girl Friday, give permission, give the go-ahead,
   give the imprimatur, give thumbs up, go along with, half a jiffy,
   half a mo, half a second, half a shake, half step, halftone, help,
   helper, helpmate, helpmeet, hour, initial, instant, interval,
   irregular, jiff, jiffy, later, leap year, less semitone,
   lieutenant, lover, lunar month, lunar year, lunation, luster,
   lustrum, mainstay, maintainer, man Friday, man-hour,
   melodic interval, microsecond, millennium, millisecond, minute,
   moment, month, moon, move, newer, next, notarize, note, number two,
   octave, other, parallel octaves, paranymph, paraprofessional,
   partisan, pass, pass on, pass upon, patron, patronize, permit,
   promote, promoter, protagonist, quarter, quinquennium, ratify,
   regular year, reliance, relocate, right hand, rubber stamp,
   run interference for, sanction, say amen to, schlock, schmatte,
   seal, sec, second-best, secondarily, secondary, seconder, secondly,
   sectary, semester, semitone, servant, session, seventh, shake,
   shift, side with, sideman, sider, sidereal year, sign,
   sign and seal, sixth, solar year, split second, sponsor, stalwart,
   stand back of, stand behind, stand by, stand-in, standby, step,
   stick by, stick up for, stroke, subordinate, subscribe to,
   subsequent, substitute, sun, support, supporter, supporting actor,
   supporting instrumentalist, surrogate, sustainer, swear and affirm,
   swear to, sympathizer, take sides with, term, third, tick, tone,
   transfer, trice, trimester, twelvemonth, twin, twink, twinkle,
   twinkling, twinned, twitch, two shakes, two-faced, two-level,
   two-ply, two-sided, two-story, twofold, undersign, understudy,
   underwrite, unison interval, upholder, validate, visa, vise,
   votary, warrant, week, weekday, well-wisher, whole step, wink,
   year, younger



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

SECOND. A measure equal to one sixtieth part of a minute. Vide Measure.