Significant other (SO) is colloquially used as a gender-neutral term for a person's partner in an intimate relationship without disclosing or presuming anything about marital status, relationship status, or sexual orientation. Synonyms with similar properties include sweetheart, better half, spouse, domestic partner, lover, soulmate, or life partner. In the United States, the term is sometimes used in invitations, such as to weddings and office parties. This use of the term has become common in the UK in correspondence from hospitals, e.g., "you may be accompanied for your appointment by a significant other".