Synonyms and related words :
Argus, Cassandra, Charley, Jeremiah, admonisher, airplane spotter, cautioner, fire patrolman, fire warden, fireguard, flagman, forward observer, lighthouse keeper, lookout, lookout man, monitor, night watchman, patrol, patroller, patrolman, picket, prophet of doom, roundsman, scout, sentinel, signaler, signalman, spotter, vedette, ward, warner, watch, watcher, watchkeeper, watchman