operative

UK: /ˈɒpərətɪv/

US: /ˈɑpərətɪv, ˈɑprətɪv, ˈɑpəˌreɪtɪv/

US: (op′ər ə tiv, op′rə tiv, op′ə rā′tiv)

WordReference Random House Learner's Dictionary of American English © 2025

op•er•a•tive /ˈɑpərətɪv, ˈɑprətɪv, ˈɑpəˌreɪtɪv/   n. [countable]

1. a person engaged or skilled in some branch of work, esp. productive or industrial work;
   worker.
2. a detective.
3. a secret agent:
   an FBI operative.

adj. 

4. • being in operation:
     The plant was fully operative.
   • being in force:
     The regulation became operative last month.
5. most important or significant;
   key:
   [before a noun] The operative word is "caution.''

See -oper-.

WordReference Random House Unabridged Dictionary of American English © 2025

op•er•a•tive  (op′ər ə tiv, op′rə tiv, op′ə rā′tiv), n. 

1. a person engaged, employed, or skilled in some branch of work, esp. productive or industrial work; worker.
2. a detective.
3. a secret agent;
   spy.

adj. 

4. operating, or exerting force, power, or influence.
5. having force;
   being in effect or operation:
   laws operative in this city.
6. effective or efficacious.
7. engaged in, concerned with, or pertaining to work or productive activity.
8. significant;
   key:
   The operative word in that sentence is "sometimes.''
9. Medicine, Surgery concerned with, involving, or pertaining to surgical operations.

• Latin operāt(us) (see operate) + Middle French -if -ive
• Middle French operatif
• 1590–1600

op′er•a•tive•ly, adv. 
op′er•a•tive•ness, op•er•a•tiv•i•ty  (op′ər ə tiv′i tē), n.  Synonyms

• 1. workman, factory hand.
• 2. investigator, agent.
• 6. effectual, serviceable.

Collins Concise English Dictionary © HarperCollins Publishers::

operative / ˈɒpərətɪv/ adjective

1. in force, effect, or operation
2. exerting force or influence
3. producing a desired effect; significant: the operative word
4. of or relating to a surgical procedure

noun

1. a worker, esp one with a special skill
2. a private detective

ˈoperatively adverb

ˈoperativeness, ˌoperaˈtivity noun