ticker

Etymology

tick + -er

noun

1. One who makes a tick mark.
   A teacher now is a typist, a printer, a laboratory assistant, a designer of work sheets and booklets, a form-filler, a ticker of boxes and a sender of returns to faculty heads, to head teachers, to education authorities and to the Ministers […] 1992, Parliamentary Debates (Hansard)
2. A measuring or reporting device, particularly one which makes a ticking sound as the measured events occur.
   The ticker was showing an increased rate of flow.
3. A ticker tape, either the traditional paper kind or a scrolling message on a screen.
   I checked the prices on the ticker one last time before placing the trade.
   To my surprise, the ticker showed that the deal had already gone through.
4. (slang) A heart, especially a human one.
   My ticker gave out and I had to go to the hospital for surgery.
5. (slang) A watch (timepiece).
6. (birdwatching, slang) A birdwatcher who aims to see (and tick off on a list) as many bird species as possible.