Quidproquo

Quid pro quo ("this for that" in Latin) most often means a more-or-less equal exchange or substitution of goods or services. English speakers often use the term to mean "a favor for a favor" and the phrases with almost identical meaning include: "barter", "give and take", "tit for tat", "this for that", and "you scratch my back, and I'll scratch yours." Other meanings are given later in this article.