A person or thing that is acting or capable of acting.
(electronics) Any component that is not passive. See Passivity (engineering).
Having the power or quality of acting; causing change; communicating action or motion; acting;—opposed to passive, that receives.
Quick in physical movement; of an agile and vigorous body; nimble.
An adjective "active" is used to describe something that is in action, working, or in force, and can also refer to certain geological features that emit hot materials or produce tremors.
Given to action; constantly engaged in action; energetic; diligent; busy
Requiring or implying action or exertion
Given to action rather than contemplation; practical; operative
Brisk; lively.
Implying or producing rapid action.
(heading, grammar) An adjective "active" is applied to verbs that are in the active voice, assert that the subject acts upon something else, and express action rather than mere existence or state.
(computing, of source code) Eligible to be processed by a compiler or interpreter.
(electronics) Not passive.
(gay sexual slang) enjoying a role in anal sex in which he penetrates, rather than being penetrated by his partner.