douille

socket (electrical socket); cartridge case (unprofessional; the correct term in the military is étui); money

Inherited from Middle French douille, from Old French doile, doelle (“the hollow part of a tool where the handle is fixed”), from Frankish *dollī, *dullī (“hollow tube, pipe”), from Proto-Germanic *dulją (“pipe”), from Proto-Indo-European *dʰel- (“curvature, hollow”). Cognate with Old High German duli, tulli (“pipe”).