(US) A sleepover party, usually held in a public place such as a church or school, in which the participants are not allowed to leave until the next morning.

(US) Standard form of all cats are grey in the dark.

(UK, sometimes vulgar and offensive) Sex is enjoyable regardless of the physical attractiveness or social station of one's partner.

Alternative spelling of in situ

Alternative form of beauty is in the eye of the beholder

A temporary replacement for another, especially at a job. / A substitution. / (mathematics) An intermediate result that must be stored temporarily during the course of a sparse matrix computation.

Lying between; neither one thing nor the other.

An interval or intervening time. / One who intervenes.

Between them.

Between / In the space between