Question

playful or out-of-the-ordinary activities; mischievous or illegal activities (use "monkey")

Accepted Answer

There's been some monkey business in connection with the bank's accounts. | Bob left the company quite suddenly. I think there was some monkey business between him and the boss's wife.

Front	playful or out-of-the-ordinary activities; mischievous or illegal activities (use "monkey")
Back	There's been some monkey business in connection with the bank's accounts. \| Bob left the company quite suddenly. I think there was some monkey business between him and the boss's wife.

Monkey Business Playful Out Of The Ordinary Activities Mischievous Illegal Connection