powder room

In reference to lavatories, an indirection developed under the influence of powder one's nose (“euphemism for use a toilet”). Compare boudoir.

powder room (plural powder rooms)

1. A room used to store gunpowder, particularly (historical) on a ship equipped with cannon.

   Are you insane? Don't take a candle into the powder room!

2. (historical) A room used to powder hair and wigs.
3. (originally US, euphemistic) Synonym of ladies' room: a lavatory intended for use by women.

   If you'll excuse me, I need to visit the powder room to see a man about a dog.

   • 1927, E.A. Park, chapter IX, in New Backgrounds for a New Age, page 173:

     They are the authors of the small powder room in the Hofbrau House at Broadway and Fifty-third Street, New York, a very modern creation.

4. (euphemistic) Synonym of half bath: a small room with a toilet and sink but no bathtub or shower.

• (gunpowder storage): powder magazine
• (powdering room): powder closet
• (lavatory for women): See Thesaurus:bathroom

• powder one's nose
• take a powder

• "powder room, n.", in the Oxford English Dictionary (2006), Oxford: Oxford University Press.