From poudre + Shimose. Calque of Japanese 下瀬火薬 (“Shimose kayaku”), from 下瀬 (Shimose, surname) + 火薬 (kayaku, “gunpowder”). Named after Japanese chemist 下瀬雅允 (Shimose Masachika) (1860–1911), the developer of the powder.
poudre Shimosa f (uncountable)