Lookout/ˈlʊkaʊt/ Definition 1 of 4Pro Tip 1/2Safety Role Used to describe someone assigned to watch for impending dangers, typically in a group setting. During the hike, Mark was the lookout for any bears. Pro Tip 2/2Criminal Activity Often refers to a person watching for police or danger during illegal actions. She agreed to be the lookout while her friends spray-painted the wall.