(operations) A service policy in which the first to arrive for service receives the service first.

If something one wishes to be done cannot be commanded done, one must find another way to achieve one's goal.

Bad things or situations always come in groups or streaks, they never come in a single way.

(slang) To fail to come up with anything; to get nowhere.

If an unfortunate event has already occurred twice, a third unfortunate event is likely to occur.

(UK, dialect, archaic) Some day soon; one of these days.

A fictional ghost in A Christmas Carol by Charles Dickens; it visits Ebenezer Scrooge in order to show his impending fate of death and loneliness in a future Christmas that is ultimately avoided.

To surprisingly succeed despite long odds; to stealthily or unobtrusively rise up from a low-status position.

(idiomatic) A person's past wrongdoings will return to negatively affect them.

Synonym of rain cats and dogs