custodian

1 a person who takes care of a property sometimes for an absent owner <the custodian made his usual rounds of the building to make sure that everything was OK> Synonyms caretaker, guardian, janitor, keeper, warden, watchman Related Words cocurator, curator; sexton, steward

2 a person or group that watches over someone or something <served as custodian of the prisoner until he could be turned over to federal authorities> Synonyms guard, guardian, keeper, lookout, minder, picket, sentinel, sentry, warden, warder, watch, watcher, watchmanRelated Words observer, patrol, spotter, surveillant, watchdog; bodyguard, convoy, defender, escort, honor guard; gatekeeper; hack [slang]

3 someone that protects <we must regard ourselves as custodians of the Earth so that its natural resources may be enjoyed by many generations to come> Synonyms protector, defender, guard, guardian, guardian angel, protectionRelated Words bodyguard, champion; lookout, sentinel, sentry, warden, warder, watch, watchdog, watchman; conserver, harborer, keeper, preserver, saver