bay window

From Middle English baywyndow, baywyndowe, bay-windowe, equivalent to bay +‎ window where bay refers to an opening between columns.

bay window (plural bay windows)

1. (architecture) A window space projecting outward from the main walls of a building and forming a bay in a room.
2. (figuratively) A protruding belly.
   • 1948, Godfrey Poage, What You Ought to Know Before Marriage‎, St. Louis: The Queen’s Work, page 12:

     Marriages that are based only on sex appeal generally fizzle out as soon as he gets a bay window and her figure becomes a bit lumpish.

   • 1982, Guy Vanderhaeghe, Man Descending, McClelland & Stewart, published 2004, →ISBN, page 126:

     Bert came hustling up, bumping his way through the kids with his bay window.

• (protruding belly): See also Thesaurus:paunch.