Galthrap

... Galthrap into his Bed, which having three Iron Spikes, very sharp, stood up- wards, so that if he had chanced to have lyen down up- on it, it was almost impossible for him to have escaped Death, but discovering it before he went[…]

... galthrap, of the first. Crest - A galthrap on a hill, ppr.

... (... galthrap, galtrap, Jackrock calthrop or crow's foot) is an antipersonnel weapon made up of two or more sharp nails or spines arranged in such a manner that one of them always points upward from a stable base (for example, a tetrahedron)[…]