Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
relationship (n.)
has long been a Standard general term for “the condition of being related to each other, usually by blood or marriage,” and for “any specifiable connection or association,” such as in The economic relationship between these two countries is vital to each. But in recent years a new, specialized and at first Conversational and Informal meaning has developed, meaning “a sexual tie between consenting adults, not involving marriage,” as in We’ve had a relationship for three years now, but we’ve never really discussed getting married. This sense is still not fully Standard, but given recent changes in the manners and values affecting such matters, it is widely used and increasingly useful in nearly all but the most Oratorical and Formal contexts, including some Edited English.
