adj.
- moving or tending to move about vigorously or frequently.
▸(of a person's mind or imagination) alert and lively.
- participating in a particular sphere or activity.
- working or in operation.
- Grammar denoting a voice of verbs in which the subject is typically the person or thing performing the action and which can take a direct object (e.g. she loved him as opposed to he was loved). The opposite of passive.
- (of a volcano) erupting or having erupted in historical times.
- (of a disease) not in remission or latent.
- having a chemical or biological effect on something.
- (of an electric circuit) capable of modifying its state or characteristics automatically in response to input or feedback.
n.
Grammar an active form of a verb.
Derivative
Etymology
ME: from L. activus, from act-, agere ‘act, do’.