Adjective
1. operative
2. at work, operant, effective, good, in effect, in force, operational, in operation, operating, working, medical procedure
3. surgical
4. preoperative, postoperative, key
5. significant, important, running
Noun
1. functional, working, functioning, secret agent
2. intelligence officer, intelligence agent, agent, private detective
2. PI, private eye, private investigator, shamus, sherlock, detective