Having the power or property of acting; tending to cause change or communicate action or motion; capable of exerting influence: opposed to passive: as, attraction is an active power.Specifically In medicine, acting quickly; producing immediate effects: as, active remedies or treatment.Having the power of quick motion, or disposition to move with speed; nimble; lively; brisk; agile: as, an active animal.Busy; constantly engaged in action; acting with vigor and assiduity: opposed to dull, slow, or indolent: as, an active officer; also to sedentary: as, an active life.In a state of action; marked by movement or operation; in actual progress or motion; not quiescent, dormant, or suspended: as, to take active proceedings against an offender; to engage in active hostilities.Hence In com., marked by quickness or frequency; brisk; lively; coming or moving freely or abundantly: as, an active trade or demand for goods; active freights or stocks. Requiring action or exertion; practical; operative; producing real effects: opposed to speculative: as, the active duties of life; the active powers of the mind.In grammar, signifying the performance and not the endurance of an action: opposed to passive.Reid uses the term to denote the will, appetites, affections, etc.; but that use has been generally condemned.The state of having a place on the active list, under full pay: used in contradistinction to being on the retired list, under reduced pay.Active regards either mind or body; there is no sinister sense of the word. The activity may be merely for its own sake. Active is opposed to lazy, inert, or quiescent: an active mind, life, person.Busy is active about something that is supposed to be useful. As applied to disposition, the word has acquired a bad sense, that of meddlesome: a busybody; he is too busy about others' affairs. An officious person is one whose efforts to be active or busy for others' benefit come, through his lack of judgment, to be regarded as annoying or intrusive. See impertinent.In psychology, representative of a type of character whose dominant characteristic is a natural and constantly renewed tendency to action.