The Collaborative International Dictionary of English v.0.48:

Quarter \Quar"ter\ (kw[aum]r"t[~e]r), n. [F. quartier, L.
   quartarius a fourth part, fr. quartus the fourth. See
   Quart.]
   1. One of four equal parts into which anything is divided, or
      is regarded as divided; a fourth part or portion; as, a
      quarter of a dollar, of a pound, of a yard, of an hour,
      etc. Hence, specifically:
      (a) The fourth of a hundred-weight, being 25 or 28 pounds,
          according as the hundredweight is reckoned at 100 or
          112 pounds.
      (b) The fourth of a ton in weight, or eight bushels of
          grain; as, a quarter of wheat; also, the fourth part
          of a chaldron of coal. --Hutton.
      (c) (Astron.) The fourth part of the moon's period, or
          monthly revolution; as, the first quarter after the
          change or full.
      (d) One limb of a quadruped with the adjacent parts; one
          fourth part of the carcass of a slaughtered animal,
          including a leg; as, the fore quarters; the hind
          quarters.
      (e) That part of a boot or shoe which forms the side, from
          the heel to the vamp.
      (f) (Far.) That part on either side of a horse's hoof
          between the toe and heel, being the side of the
          coffin.
      (g) A term of study in a seminary, college, etc, etc.;
          properly, a fourth part of the year, but often longer
          or shorter.
      (h) pl. (Mil.) The encampment on one of the principal
          passages round a place besieged, to prevent relief and
          intercept convoys.
      (i) (Naut.) The after-part of a vessel's side, generally
          corresponding in extent with the quarter-deck; also,
          the part of the yardarm outside of the slings.
      (j) (Her.) One of the divisions of an escutcheon when it
          is divided into four portions by a horizontal and a
          perpendicular line meeting in the fess point.
          [1913 Webster]

   Note: When two coats of arms are united upon one escutcheon,
         as in case of marriage, the first and fourth quarters
         display one shield, the second and third the other. See
         Quarter, v. t., 5.
         [1913 Webster]
      (k) One of the four parts into which the horizon is
          regarded as divided; a cardinal point; a direction'
          principal division; a region; a territory.
          [1913 Webster]

                Scouts each coast light-armed scour,
                Each quarter, to descry the distant foe.
                                                  --Milton.
          [1913 Webster]
      (l) A division of a town, city, or county; a particular
          district; a locality; as, the Latin quarter in Paris.
      (m) (Arch.) A small upright timber post, used in
          partitions; -- in the United States more commonly
          called stud.
      (n) (Naut.) The fourth part of the distance from one point
          of the compass to another, being the fourth part of
          11[deg] 15', that is, about 2[deg] 49'; -- called also
          quarter point.
          [1913 Webster]
          [1913 Webster]

   2. Proper station; specific place; assigned position; special
      location.
      [1913 Webster]

            Swift to their several quarters hasted then
            The cumbrous elements.                --Milton.
      [1913 Webster] Hence, specifically:
      (a) (Naut.) A station at which officers and men are posted
          in battle; -- usually in the plural.
      (b) Place of lodging or temporary residence; shelter;
          entertainment; -- usually in the plural.
          [1913 Webster]

                The banter turned as to what quarters each would
                find.                             --W. Irving.
          [1913 Webster]
      (c) pl. (Mil.) A station or encampment occupied by troops;
          a place of lodging for soldiers or officers; as,
          winter quarters.
      (d) Treatment shown by an enemy; mercy; especially, the
          act of sparing the life a conquered enemy; a
          refraining from pushing one's advantage to extremes.
          [1913 Webster]

                He magnified his own clemency, now they were at
                his mercy, to offer them quarter for their
                lives.                            --Clarendon.
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                Cocks and lambs . . . at the mercy of cats and
                wolves . . . must never expect better quarter.
                                                  --L'Estrange.
          [1913 Webster]

   3. Friendship; amity; concord. [Obs.] To keep quarter, to
      keep one's proper place, and so be on good terms with
      another. [Obs.]
      [1913 Webster]

            In quarter, and in terms like bride and groom.
                                                  --Shak.
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            I knew two that were competitors for the secretary's
            place, . . . and yet kept good quarter between
            themselves.                           --Bacon.
      [1913 Webster]

   False quarter, a cleft in the quarter of a horse's foot.

   Fifth quarter, the hide and fat; -- a butcher's term.

   On the quarter (Naut.), in a direction between abeam and
      astern; opposite, or nearly opposite, a vessel's quarter.


   Quarter aspect. (Astrol.) Same as Quadrate.

   Quarter back (Football), the player who has position next
      behind center rush, and receives the ball on the snap
      back.

   Quarter badge (Naut.), an ornament on the side of a vessel
      near, the stern. --Mar. Dict.

   Quarter bill (Naut.), a list specifying the different
      stations to be taken by the officers and crew in time of
      action, and the names of the men assigned to each.

   Quarter block (Naut.), a block fitted under the quarters of
      a yard on each side of the slings, through which the clew
      lines and sheets are reeved. --R. H. Dana, Jr.

   Quarter boat (Naut.), a boat hung at a vessel's quarter.

   Quarter cloths (Naut.), long pieces of painted canvas, used
      to cover the quarter netting.

   Quarter day, a day regarded as terminating a quarter of the
      year; hence, one on which any payment, especially rent,
      becomes due. In matters influenced by United States
      statutes, quarter days are the first days of January,
      April, July, and October. In New York and many other
      places, as between landlord and tenant, they are the first
      days of May, August, November, and February. The quarter
      days usually recognized in England are 25th of March (Lady
      Day), the 24th of June (Midsummer Day), the 29th of
      September (Michaelmas Day), and the 25th of December
      (Christmas Day).

   Quarter face, in fine arts, portrait painting, etc., a face
      turned away so that but one quarter is visible.

   Quarter gallery (Naut.), a balcony on the quarter of a
      ship. See Gallery, 4.

   Quarter gunner (Naut.), a petty officer who assists the
      gunner.

   Quarter look, a side glance. [Obs.] --B. Jonson.

   Quarter nettings (Naut.), hammock nettings along the
      quarter rails.

   Quarter note (Mus.), a note equal in duration to half a
      minim or a fourth of semibreve; a crochet.

   Quarter pieces (Naut.), several pieces of timber at the
      after-part of the quarter gallery, near the taffrail.
      --Totten.

   Quarter point. (Naut.) See Quarter, n., 1
      (n) .

   Quarter railing, or Quarter rails (Naut.), narrow molded
      planks reaching from the top of the stern to the gangway,
      serving as a fence to the quarter-deck.

   Quarter sessions (Eng. Law), a general court of criminal
      jurisdiction held quarterly by the justices of peace in
      counties and by the recorders in boroughs.

   Quarter square (Math.), the fourth part of the square of a
      number. Tables of quarter squares have been devised to
      save labor in multiplying numbers.

   Quarter turn, Quarter turn belt (Mach.), an arrangement
      in which a belt transmits motion between two shafts which
      are at right angles with each other.

   Quarter watch (Naut.), a subdivision of the full watch (one
      fourth of the crew) on a man-of- war.

   To give quarter, or To show quarter (Mil.), to accept as
      prisoner, on submission in battle; to forbear to kill, as
      a vanquished enemy.

   To keep quarter. See Quarter, n., 3.
      [1913 Webster]

WordNet (r) 3.0 (2006):

quarter note
    n 1: a musical note having the time value of a quarter of a
         whole note [syn: quarter note, crotchet]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "quarter note":
   accidental, breve, crotchet, demisemiquaver, dominant,
   dominant note, double whole note, eighth note, enharmonic,
   enharmonic note, flat, half note, hemidemisemiquaver, minim,
   musical note, natural, note, patent note, quaver, report,
   responding note, semibreve, semiquaver, shaped note, sharp,
   sixteenth note, sixty-fourth note, spiccato, staccato,
   sustained note, tercet, thirty-second note, tone, triplet,
   whole note