simultum

simultum [LL; cf. 1 simultas], worm or insect found in the horns and head of sheep that causes them to attack each other. hoc simultum, -i, i. vermis quidam in cornibus arietum qui facit eos cornupetare Osb. Glouc. Deriv. 532; a worme ‥ gurgulio ‥ ~um est vermis in capite vervecis CathA.