blackouts

noun

1. (form-of, plural)plural of blackout
2. (historical, plural, plural-only, slang)Long, dark-coloured underwear worn by the WAAF in winter.

   “[…] her blackouts. When the Officer inspected everything went well. The only thing was that two of our WAAF were not wearing any knickers at all!”

   “We had what were called the ‘blackouts’ and ‘twilights’. The blackouts were a dark sort of long-legged knickers, dark wintry ones, and the twilights were a lighter blue in a sort of Celanese material.”