operative

adjective

1 although the act has been passed by parliament, it is not operative at the moment:

in force, in operation, effective, in effect, valid.

▷antonyms invalid.

2 the steam railroad is still operative:

functioning, working, running, up and running, in operation, in use, in action, going;

operational, workable, serviceable, functional, usable, in working order/condition, viable.

▷antonyms out of order.

3 “might” is the operative word:

key, significant, relevant, applicable, pertinent, apposite, germane, apropos, crucial, critical, main, chief, major, central, pivotal, fundamental, vital, important, essential.

▷antonyms irrelevant.

noun

1 the operatives clean the machines at the end of every shift:

machinist, (machine) operator, mechanic, engineer, driver, worker, workman, (factory) hand, artisan, craftsman, craftswoman, blue-collar worker;

British machine minder.

2 North American a special operative of the CIA:

agent, secret agent, undercover agent, spy, mole, plant, double agent, counterspy;

North American, informal spook;

archaic intelligencer;

archaic , informal beagle.

3 North American employ a private operative:

detective, private detective, investigator, private investigator, sleuth, shadow;

British enquiry agent;

informal private eye, tail;

North American, informal , dated gumshoe, bogey, dick.