The Oxford Thesaurus An A-Z Dictionary of Synonyms - operative adj.

1) See operation, 5, above. --n. 2) worker, hand, employee; craftsman, craftswoman, artisan, mechanic, machinist: We hired two more lathe operatives today. 3 private detective, (private) investigator, Colloq private eye, sleuth, Brit sleuth-hound, US P.I., gumshoe, Slang (private) dick, US shamus, eye: Our operatives reported that Jones had been seen in the company of a known enemy agent. 4) espionage or intelligence agent, counter-espionage or counter-intelligence agent, spy, counter-spy, undercover agent or man, (FBI or CIA) agent, US G-man, Colloq US company man, member of the firm: We had an operative at the top level of the NKVD.