4N-COUNT [usually adjective NOUN]精明圆滑的人;善于取巧的人 If you call someone a good operator, you mean that they are skilful at achieving what they want, often in a slightly dishonest way. 精明圆滑的人;善于取巧的人 [informal]
He was a smart operator. Don't underestimate him.
他这个人精明圆滑,可别小瞧了他。
...one of the shrewdest political operators in the Arab World. [+ in]