[n] someone who can be employed as a detective to collect information
[n] a person secretly employed in espionage for a government
[adj] being in force or having or exerting force; "operative regulations"; "the major tendencies operative in the American political system"
[adj] (of e.g. a machine) performing or capable of performing; "in running (or working) order"; "a functional set of brakes"
[adj] relating to or requiring or amenable to treatment by surgery especially as opposed to medicine; "a surgical appendix"; "a surgical procedure"; "operative dentistry"
[adj] effective; producing a desired effect; "the operative word"
[adj] of or relating to a surgical operation; "operative surgery"