Source : Webster's Revised Unabridged Dictionary (1913)

Play \Play\, v. i. [imp. & p. p. {Played}; p. pr. & vb. n.
   {Playing}.] [OE. pleien, AS. plegian, plegan, to play, akin
   to plega play, game, quick motion, and probably to OS. plegan
   to promise, pledge, D. plegen to care for, attend to, be
   wont, G. pflegen; of unknown origin. [root]28. Cf. {Plight},
   n.]
   1. To engage in sport or lively recreation; to exercise for
      the sake of amusement; to frolic; to spot.

            As Cannace was playing in her walk.   --Chaucer.

            The lamb thy riot dooms to bleed to-day, Had he thy
            reason, would he skip and play!       --Pope.

            And some, the darlings of their Lord, Play smiling
            with the flame and sword.             --Keble.

   2. To act with levity or thoughtlessness; to trifle; to be
      careless.

            ``Nay,'' quod this monk, ``I have no lust to
            pleye.''                              --Chaucer.

            Men are apt to play with their healths. --Sir W.
                                                  Temple.

   3. To contend, or take part, in a game; as, to play ball;
      hence, to gamble; as, he played for heavy stakes.

   4. To perform on an instrument of music; as, to play on a
      flute.

            One that . . . can play well on an instrument.
                                                  --Ezek.
                                                  xxxiii. 32.

            Play, my friend, and charm the charmer. --Granville.

   5. To act; to behave; to practice deception.

            His mother played false with a smith. --Shak.

   6. To move in any manner; especially, to move regularly with
      alternate or reciprocating motion; to operate; to act; as,
      the fountain plays.

            The heart beats, the blood circulates, the lungs
            play.                                 --Cheyne.

   7. To move gayly; to wanton; to disport.

            Even as the waving sedges play with wind. --Shak.

            The setting sun Plays on their shining arms and
            burnished helmets.                    --Addison.

            All fame is foreign but of true desert, Plays round
            the head, but comes not to the heart. --Pope.

   8. To act on the stage; to personate a character.

            A lord will hear your play to-night.  --Shak.

            Courts are theaters where some men play. --Donne.

   {To play into a person's hands}, to act, or to manage
      matters, to his advantage or benefit.

   {To play off}, to affect; to feign; to practice artifice.

   {To play upon}.
      (a) To make sport of; to deceive.

                Art thou alive? Or is it fantasy that plays upon
                our eyesight.                     --Shak.
      (b) To use in a droll manner; to give a droll expression
          or application to; as, to play upon words.

Playing \Play"ing\,
   a. & vb. n. of {Play}.

   {Playing cards}. See under {Card}.

Source : WordNet®

playing
     n 1: the act of playing a musical instrument
     2: the action of taking part in a game or sport or other
        recreation
     3: the performance of a part or role in a drama [syn: {acting},
         {playacting}, {performing}]