the.com/powder room

means A small bathroom, typically a half-bath with just a toilet and sink, set aside for guests on the main floor of a home.

from A genteel euphemism rooted in literal nose-powdering: by the early 20th century, a 'powder room' was a space where ladies could retreat to refresh their makeup, away from company. The phrase let polite society gesture toward the toilet without naming it — the act of dabbing on face powder standing in for everything else one might do behind a closed door. Earlier still, in the 18th century, 'powder room' meant something quite different and unglamorous: the room aboard a warship where gunpowder was stored. The cosmetic sense is the one that stuck in the modern house, where the powder is long gone but the polite pretense remains.