A watch (timepiece).
A heart, especially a human one.
One who makes a tick mark.
A birdwatcher who aims to see (and tick off on a list) as many bird species as possible.
A ticker tape, either the traditional paper kind or a scrolling message on a screen.
A measuring or reporting device, particularly one which makes a ticking sound as the measured events occur.
A watch that is worn on a strap or band fastened around the wrist