adherent UK /ædˈ(h)ɪə.ɹənt/US /ædˈ(h)ɪɹ.ənt/adjective 4noun 1forms 3 adjective4 •Adhesive, sticking to something.Close to the cliff with both his hands he clung And stuck adherent, and suspended hung. — 1738 •Showing adherence to a treatment.Half (49.9%) of patients were adherent to their regimens, 42.6% were underadherent, and 7.6% had medication oversupply. — 2007 •Having the quality of clinging or sticking fast to something. •Attaching or pressing against a different organ. noun1 •A person who has membership in some group, association, or religion. formsadherents · more adherent · most adherent