Sentinel — synonyms, definition

1. sentinel (Noun)

alertness defender direction guard guardian guidance lighthouse look-out lookout lookout man observation patrol patrolman picket protector scout sentry spotter vigil ward • • •

sentinel (Noun) — A person employed to keep watch for some anticipated event. ex. "the sentinel stayed in his box to avoid the cold"

security guard watcher watchman

2. sentinel (Verb)

sentinel (Verb) — Watch over or post as a guard.