An au pair (English pronunciation: /oʊˈpɛər/; plural: au pairs) is a domestic assistant from a foreign country working for, and living as part of, a host family. Typically, au pairs take on a share of the family's responsibility for childcare as well as some housework, and receive a monetary allowance for personal use. Au pair arrangements are subject to government restrictions which specify an age range usually from mid-late teens to mid to late twenties; some countries explicitly limit the arrangement to females.
Arrangements differ between Europe, where the concept originated, and North America. In Europe, au pairs are only supposed to work part-time, and they often also study part-time, generally focusing on the language of the host country. In the United States, they may provide full-time childcare. In 1969, the European Agreement on Au Pair Placement was signed, and it came into force in 1971.
The title comes from the French term au pair, meaning "at par" or "equal to", indicating that the relationship is intended to be one of equals: the au pair is intended to become a member of the family, albeit a temporary one, rather than a traditional domestic worker.
Although it is not as simple to acquire au pair status as it was in 1840, the expression was used to indicate economic parity between the "employer" and their "employee". The expression au pair was used in this sense in 1840 by Honoré de Balzac:
Sylvie Rogron fut envoyée à cent écus de pension en apprentissage....Deux ans après, elle était au pair: si elle ne gagnait rien, ses parents ne payaient plus rien pour son logis et sa nourriture (BALZAC, Pierrette, 1840, p.17).
(Sylvie Rogron was sent out to an apprenticeship at an annual cost of one hundred écus....After two years, she was au pair; she wasn't earning anything, but at least her parents did not have to pay for her room and board.)