a person who follows or upholds a leader, cause, etc.; supporter; follower.

sticking; clinging; adhering

an adherent substance.

bound by contract or other formal agreement

the nations adherent to the Geneva Convention.

Biology . adnate.

Grammar . standing before and modifying a noun; attributive.

noun

advocate , aficionado , backer , believer , card-carrying member , devotee , disciple , enthusiast , fan , hanger-on , cohort , henchman , minion , partisan , satellite , supporter , -ist , -ite , acolyte , ally , follower , pupil , upholder , votary