Lookout is a term used to describe the act of keeping WATCH or being on guard. OBSERVATION (11 letters) is the act of closely watching or noticing something. WATCHTOWER (10 letters) is a structure built to provide a high vantage point for OBSERVATION. PATROL (6 letters) is the act of regularly walking or driving around an area to keep WATCH. VIGILANCE (9 letters) is the state of being alert and watchful. SURVEILLANCE (12 letters) is the act of monitoring or observing from a distance. CUPOLA (6 letters) is a small dome-like structure built on top of a larger structure to provide a lookout point. WATCH (5 letters) is the act of keeping guard or being on alert. VIGIL (5 letters) is the act of staying awake during the night to keep WATCH. EYER (4 letters) is someone who looks out for something. SENTRY (6 letters) is a soldier or guard posted to keep WATCH. SENTINEL (8 letters) is a guard or lookout who stands WATCH.