Source : Webster's Revised Unabridged Dictionary (1913)

Coy \Coy\, v. t. [imp. & p. p. {Coyed} (koid); p. pr. & vb. n.
   {Coying}.]
   1. To allure; to entice; to decoy. [Obs.]

            A wiser generation, who have the art to coy the
            fonder sort into their nets.          --Bp. Rainbow.

   2. To caress with the hand; to stroke.

            Come sit thee down upon this flowery bed, While I
            thy amiable cheeks do coy.            --Shak.

Coy \Coy\, v. i.
   1. To behave with reserve or coyness; to shrink from approach
      or familiarity. [Obs.]

            Thus to coy it, With one who knows you too! --Rowe.

   2. To make difficulty; to be unwilling. [Obs.]

            If he coyed To hear Cominius speak, I 'll keep at
            home.                                 --Shak.

Coy \Coy\ (koi), a. [OE. coi quiet, still, OF. coi, coit, fr.L.
   quietus quiet, p. p. of quiescere to rest, quie rest; prob.
   akin to E. while. See {While}, and cf. {Quiet}, {Quit},
   {Quite}.]
   1. Quiet; still. [Obs.] --Chaucer.

   2. Shrinking from approach or familiarity; reserved; bashful;
      shy; modest; -- usually applied to women, sometimes with
      an implication of coquetry.

            Coy, and difficult to win.            --Cowper.

            Coy and furtive graces.               --W. Irving.

            Nor the coy maid, half willings to be pressed, Shall
            kiss the cup, to pass it to the rest. --Goldsmith.

   3. Soft; gentle; hesitating.

            Enforced hate, Instead of love's coy touch, shall
            rudely tear thee.                     --Shak.

   Syn: Shy; shriking; reserved; modest; bashful; backward;
        distant.

Source : WordNet®

coy
     adj 1: affectedly modest or shy especially in a playful or
            provocative way [syn: {demure}, {overmodest}]
     2: showing marked and often playful or irritating evasiveness
        or reluctance to make a definite or committing statement;
        "a politician coy about his intentions"
     3: modestly or warily rejecting approaches or overtures; "like
        a wild young colt, very inquisitive but very coy and not
        to be easily cajoled"