ticker

One who makes a tick mark.

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.”

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.”

A heart, especially a human one.

“My ticker gave out and I had to go to the hospital for surgery.”

A birdwatcher who aims to see (and tick off on a list) as many bird species as possible.