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

look attentively

“watch a basketball game”

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

observe or determine by looking

see or watch

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

a purposeful surveillance to guard or observe

observe with attention

“They watched as the murderer was executed”

a small portable timepiece

follow with the eyes or the mind

“The world is watching Sarajevo”

be vigilant, be on the lookout or be careful