(idiomatic) To permit events to proceed or a situation to develop without intervention or interference.

Children should behave well and be quiet, especially in the presence of adults.

Not generic.

brown butter

plural of New Taiwan dollar

(idiomatic) With very few clothes on; revealing lots of one's body.

With very few clothes on.

The currency of Taiwan.

Used to indicate that somebody does not wish to be disturbed, e.g. a sign on a hotel room door, or a "busy" mode of an instant messenger.

(espionage) The assumption of a covert role in an organization which does not have ties to the government of the operative in question.