cross bit - a rock drill having cruciform cutting edges; used in mining

drill - a tool with a sharp point and cutting edges for making holes in hard materials (usually rotating rapidly or by repeated blows)

star drill - a steel rock drill with a star-shaped point that is used for making holes in stones or masonry; it is operated by hitting the end with a hammer while rotating it between blows

straight flute, straight-fluted drill - a rock drill with straight flutes

invertebrate - any animal lacking a backbone or notochord; the term is not used as a scientific classification