Source : Webster's Revised Unabridged Dictionary (1913)

Ticker \Tick"er\, n.
   A telegraphic receiving instrument that automatically prints
   off stock quotations ({stock ticker}) and other news on a
   paper ribbon or ``tape.''

Ticker \Tick"er\, n. [See {Tick}.]
   One who, or that which, ticks, or produces a ticking sound,
   as a watch or clock, a telegraphic sounder, etc.

Source : WordNet®

ticker
     n 1: the hollow muscular organ located behind the sternum and
          between the lungs; its rhythmic contractions pump blood
          through the body; "he stood still, his heart thumping
          wildly" [syn: {heart}, {pump}]
     2: a small portable timepiece [syn: {watch}]
     3: character printer that automatically prints stock quotations
        on tickertape [syn: {stock ticker}]