a person who guards or watches, as at a prison or gate.

a person who assumes responsibility for another's behavior

He refused to be his brother's keeper.

a person who owns or operates a business (usually used in combination)

a hotelkeeper.

a person who is responsible for the maintenance of something (often used in combination)

a zookeeper; a groundskeeper.

a person charged with responsibility for the preservation and conservation of something valuable, as a curator or game warden.

a person who conforms to or abides by a requirement

a keeper of his word.

a fish that is of sufficient size to be caught and retained without violating the law.

Football . a play in which the quarterback retains the ball and runs with it, usually after faking a hand-off or pass.

something that serves to hold in place, retain, etc., as on a door lock.

something that lasts well, as a fruit.

guard ring.

an iron or steel bar placed across the poles of a permanent horseshoe magnet for preserving the strength of the magnet during storage.

noun

archivist , attendant , caretaker , conservator , curator , custodian , defender , guard , jailer , lookout , overseer , protector , sentinel , sentry , steward , superintendent , supervisor , warden , chaperone , constable , escort , guardian , janitor , manager , warder , watchman