—adj.
1 a consisting in or marked by action; energetic; diligent (leads an active life; an active helper). b able to move about or accomplish practical tasks (infirmity made him less active).
2 working, operative (an active volcano).
3 originating action; not merely passive or inert (active support; active ingredients).
4 radioactive.
5 Gram. designating the voice that attributes the action of a verb to the person or thing from which it logically proceeds (e.g. of the verbs in guns kill; we saw him).
—n. Gram. the active form or voice of a verb.
Phrases and idioms:
active carbon = activated carbon (see ACTIVATE). active list Mil. a list of officers available for service. active service full-time service in the armed forces.
Derivatives:
actively adv. activeness n.
Etymology: ME f. OF actif -ive or L activus (as ACT v.)
Useful english dictionary. 2012.