Women's knickers worn in wartime Britain (1939-1945). Often
made of nylon/parachute silk.
Possible derivation: said to come down without a fight. (analogy with German aircraft of same name).
Underwear that has been worn for several days in hot, sweaty, sharty conditions.They reek so badly, one could use them to interrogate a suspect. He will spill the beans pretty quickly.
"For fuck sake 007 change your underwear the place stinks of arse" "Not yet, Felix old man, we still haven't found the bomb. Another hour in these Interrogation knickers and they'll be ready for that cunt Goldfinger.