watch

A person employed to keep watch for some anticipated event.

A period of time (4 or 2 hours) during which some of a ship's crew are on duty.

The period during which someone (especially a guard) is on duty.

A purposeful surveillance to guard or observe.

A small portable timepiece.

The rite of staying awake for devotional purposes (especially on the eve of a religious festival).

Look attentively.

“watch a basketball game”

See or watch.

Find out, learn, or determine with certainty, usually by making an inquiry or other effort.

Observe with attention.

“They watched as the murderer was executed”

Follow with the eyes or the mind.

“The world is watching Sarajevo”

Be vigilant, be on the lookout or be careful.

Observe or determine by looking.