active

active - noun

chemical agent capable of activity

the voice used to indicate that the grammatical subject of the verb is performing the action or causing the happening denoted by the verb

a person who is a participating member of an organization

active - adjective

tending to become more severe or wider in scope
disposed to take action or effectuate change
characterized by energetic activity
exerting influence or producing a change or effect
full of activity or engaged in continuous activity
(of the sun) characterized by an increased occurrence of sunspots and flares and radio emissions
expressing that the subject of the sentence has the semantic function of actor:
(used of verbs (e.g. `to run') and participial adjectives (e.g. `running' in `running water')) expressing action rather than a state of being
(of e.g. volcanos) capable of erupting
(of e.g. volcanos) erupting or liable to erupt
engaged in full-time work
engaged in or ready for military or naval operations
taking part in an activity
in operation

active - thesaurus