/ ˌəʊ ˈpeə(r); NAmE ˌoʊ ˈper/ noun
( BrE ) a young person, usually a woman, who lives with a family in a foreign country in order to learn the language. An au pair helps in the house and takes care of children and receives a small wage.
••
WORD ORIGIN
late 19th cent.: from French , literally on equal terms . The phrase was originally adjectival, describing an arrangement between two parties paid for by the exchange of mutual services; the noun usage dates from the 1960s.