Source : Webster's Revised Unabridged Dictionary (1913)

Cue \Cue\ (k[=u]), n. [ OF. coue, coe, F. queue, fr. L. coda,
   cauda, tail. Cf. {Caudal}, {Coward}, {Queue}.]
   1. The tail; the end of a thing; especially, a tail-like
      twist of hair worn at the back of the head; a queue.

   2. The last words of a play actor's speech, serving as an
      intimation for the next succeeding player to speak; any
      word or words which serve to remind a player to speak or
      to do something; a catchword.

            When my cue comes, call me, and I will answer.
                                                  --Shak.

   3. A hint or intimation.

            Give them [the servants] their cue to attend in two
            lines as he leaves the house.         --Swift.

   4. The part one has to perform in, or as in, a play.

            Were it my cueto fight, I should have known it
            Without a prompter.                   --Shak.

   5. Humor; temper of mind. [Colloq.] --Dickens.

   6. A straight tapering rod used to impel the balls in playing
      billiards.

Cue \Cue\, v. t.
   To form into a cue; to braid; to twist.

Cue \Cue\, n. [From q, an abbreviation for quadrans a farthing.]
   A small portion of bread or beer; the quantity bought with a
   farthing or half farthing. [Obs.]

   Note: The term was formerly current in the English
         universities, the letter q being the mark in the
         buttery books to denote such a portion. --Nares.

               Hast thou worn Gowns in the university, tossed
               logic, Sucked philosophy, eat cues? --Old Play.

Source : WordNet®

cue
     v : assist (somebody acting or reciting) by suggesting the next
         words of something forgotten or imperfectly learned [syn:
          {prompt}, {remind}]

cue
     n 1: an actor's line that immediately precedes and serves as a
          reminder for some action or speech
     2: evidence that helps to solve a problem [syn: {clue}, {clew}]
     3: a stimulus that provides information about what to do [syn:
        {discriminative stimulus}]
     4: sports implement consisting of a tapering rod used to strike
        a cue ball in pool or billiards [syn: {cue stick}, {pool
        cue}, {pool stick}]