mother-in-law unit
n.— «In Colleyville, owners can buy a small, adjacent room, often called a “mother-in-law unit” or “au pair unit.” Some town houses in Bedford and North Richland Hills have front porches.» —“Some accept town houses, others not so much” by Sarah Bahari Telegram-Star (Dallas, Texas) July 8, 2006. (source: Double-Tongued Dictionary)
Further reading
Enthusiastic book recommendations! Martha’s savoring the biography of Alexander von Humboldt, the 19th-century explorer, polymath, and naturalist who revolutionized our understanding of nature and predicted the effects of human activity on...
The words tough, through, and dough all end in O-U-G-H. So why don’t they rhyme? A lively new book addresses the many quirks of English by explaining the history of words and phrases. And: have you ever been in a situation where a group makes...