operative

adjective

• 1functioning; having effect:the transmitter is operative the mining ban would remain operative
• [attributive] (of a word) having the most relevance or significance in a phrase or sentence:a young man, and the operative word is young, should go into the armed services at around seventeen

• 2 [attributive] of or relating to surgery:they had wounds needing operative treatment

noun

• a worker, especially a skilled one in a manufacturing industry.
• a private detective or secret agent.