operative

1. ADJ A system or service that is operative is working or having an effect. (系统、服务) 起作用的[正式]

The commercial telephone service was no longer operative. 商业电话服务不起作用了。

2. N-COUNT An operative is a worker, especially one who does work with their hands. 技工[正式]

In an automated car plant there is not a human operative to be seen. 在全自动汽车制造厂，一个工人也看不到。

3. N-COUNT An operative is someone who works for a government agency such as the intelligence service. 特工人员[美国英语]

Naturally the CIA wants to protect its operatives. 中央情报局当然想保护自己的特工人员。

4. PHRASE If you describe a word as the operative word, you want to draw attention to it because you think it is important or exactly true in a particular situation. 关键词

As long as the operative word is "greed," you can't count on people keeping the costs down. 只要关键词是“贪婪”，你就不能指望人们降低开销。