defender

noun

A person who defends someone or something.

SYNONYMS

adherentadvocateapologistapostlebackerbelieverbodyguardbolsterercaretakerchampioncustodianendorserexponentflagbearerguardguardiankeeperoverseerpreserverpromoterproponentprotectorstandard-bearerstewardsuperintendentsupportersustainertorchbearertrusteeupholderwatchdog