A person who is active in a cause. …

Of human actions: done (as opposed to suffered), voluntary; actif cursing, self-excommunication. …

(a) Blameless, innocent; upright; guileless, artless; (b) of the eyes:?innocent, not sinful; ?sound, healthy; -- used fig. …

(a) Inadequate for its intended purpose, insufficient, limited in operation or action (b) flawed, defective; also, inferior in physical form; of animals, organisms: primitive, lower [sometimes……