a Having the power or quality of acting; causing change; communicating action or motion; acting; — opposed to passive, that receives; as, certain active principles; the powers of the mind.
a Quick in physical movement; of an agile and vigorous body; nimble; as, an active child or animal.
a In action; actually proceeding; working; in force; — opposed to quiescent, dormant, or extinct.
a Given to action; constantly engaged in action; energetic; diligent; busy; — opposed to dull, sluggish, indolent, or inert; as, an active man of business; active mind; active zeal.
a Requiring or implying action or exertion; — opposed to sedentary or to tranquil; as, active employment or service; active scenes.
a Given to action rather than contemplation; practical; operative; — opposed to speculative or theoretical; as, an active rather than a speculative statesman.
a Brisk; lively; as, an active demand for corn.
a (grammar) Applied to a form of the verb; — opposed to passive. See active voice.
a (grammar) Applied to verbs which assert that the subject acts upon or affects something else; transitive.
a (grammar) Applied to all verbs that express action as distinct from mere existence or state.
a (qualifier|gay sexual slang)(qualifier|of a homosexual man) enjoying a role in anal sex in which he penetrates, rather than being penetrated by his partner
n A person or thing that is acting or capable of acting.