Answer: cantharis

AnswerCrossword Clue
canthariscommon European blister beetle, Cantharis (Lytta) vesicatoria, that yields this preparation
cantharispreparation of powdered blister beetles, esp. the Spanish fly, used medicinally as a counterirritant, diuretic, and aphrodisiac
cantharisa beetle with an elongated cylindrical body of a brilliant green color, aka Spanish fly also CANTHARID