active

adjective Etymology: Middle English, from Anglo-French or Latin; Anglo-French actif, from Latin activus, from actus, past participle of agere to drive, do — more at agent Date: 14th century 1. characterized by action rather than by contemplation or speculation <

an active life

> 2. producing or involving action or movement 3. a. 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

> b. expressing action as distinct from mere existence or state 4. quick in physical movement ; lively 5. marked by vigorous activity ; busy <

the stock market was active

> 6. requiring vigorous action or exertion <

active sports

> 7. having practical operation or results ; effective <

an active law

> 8. a. disposed to action ; energetic <

took an active interest

> b. engaged in an action or activity <

an active club member

> c. of a volcano currently erupting or likely to erupt — compare dormant 2a, extinct 1b d. characterized by emission of large amounts of electromagnetic energy <

an active galactic nucleus

> 9. engaged in full-time service especially in the armed forces <

active duty

> 10. marked by present operation, transaction, movement, or use <

an active account

> 11. a. capable of acting or reacting ; reacting readily <

active nitrogen

> <

active ingredients

> b. tending to progress or to cause degeneration <

active tuberculosis

> c. of an electronic circuit element capable of controlling voltages or currents d. (1) requiring the expenditure of energy <

active calcium ion uptake

> (2) functioning by the emission of radiant energy or sound <

radar is an active sensor

> 12. still eligible to win the pot in poker 13. moving down the line ; visiting in the set — used of couples in contredanses or square dances • active noun • actively adverb • activeness noun