From Longman Dictionary of Contemporary Englishkept womanˌkept ˈwoman noun [countable] old-fashionedSY a woman who is given a place to live, money, and clothes by a man who visits her for sex – often used humorously SYN mistress
Examples from the Corpus
kept woman• Which same meant, thought Markby, that he was saying Harriet wasn't a kept woman. 