shake-down

A shake-down is a thorough search, especially of a person or premises by police or guards looking for contraband: The guards conducted a shake-down of the cell block.

It also means an extortion scheme—demanding money through threats or intimidation: The protection racket was just a shake-down.

A shake-down cruise or flight tests a new vessel or aircraft to identify problems before regular service.

As a verb, to shake down someone is to extort them, or to search them thoroughly.