A tick is a written mark like a V: ?. It is used to show that something is correct or has been selected or dealt with.

If you tick something that is written on a piece of paper, you put a tick next to it.

When a clock or watch ticks, it makes a regular series of short sounds as it works.

The tick of a clock or watch is the series of short sounds it makes when it is working, or one of those sounds.

You can use tick to refer to a very short period of time.

If you talk about what makes someone tick, you are talking about the beliefs, wishes, and feelings that make them behave in the way that they do.

A tick is a small creature which lives on the bodies of people or animals and uses their blood as food.