1. (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.

2. (a.) Quick in physical movement; of an agile and vigorous body; nimble; as, an active child or animal.

3. (a.) In action; actually proceeding; working; in force; -- opposed to quiescent, dormant, or extinct; as, active laws; active hostilities; an active volcano.

4. (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.

5. (a.) Requiring or implying action or exertion; -- opposed to sedentary or to tranquil; as, active employment or service; active scenes.

6. (a.) Given to action rather than contemplation; practical; operative; -- opposed to speculative or theoretical; as, an active rather than a speculative statesman.

7. (a.) Brisk; lively; as, an active demand for corn.

8. (a.) Implying or producing rapid action; as, an active disease; an active remedy.

9. (a.) Applied to a form of the verb; -- opposed to passive. See Active voice, under Voice.

10. (a.) Applied to verbs which assert that the subject acts upon or affects something else; transitive.

11. (a.) Applied to all verbs that express action as distinct from mere existence or state.