: characterized by action rather than by contemplation or speculation
: producing or involving action or movement
of a verb form or voice
: asserting that the person or thing represented by the grammatical subject performs the action represented by the verb
- Hits in "he hits the ball" is active.
: expressing action as distinct from mere existence or state
- active verbs such as "eat" and "sing"
: quick in physical movement : lively
: marked by vigorous activity : busy
- The stock market was active.
: requiring vigorous action or exertion
: having practical operation or results : effective
: engaged in an action or activity
of a volcano
: currently erupting or likely to erupt — compare dormant 2a, extinct 1b
: characterized by emission of large amounts of electromagnetic energy
- an active galactic nucleus
: engaged in full-time service especially in the armed forces
: marked by present operation, transaction, movement, or use
: capable of acting or reacting : reacting readily
of an electronic circuit element
: capable of controlling voltages or currents
: requiring the expenditure of energy
- active calcium ion uptake
: functioning by the emission of radiant energy or sound
- radar is an active sensor
: still eligible to win the pot in poker
: moving down the line : visiting in the set
—used of couples in contra dances or square dances
: producing active immunity
- Active immunization against Bordetella pertussis, the causative agent of whooping cough, is now usually achieved with combined pertussis-tetanus-diphtheria (DTP) vaccine.
- —Scientific American Medicine