n. The horny, nail-like covering of the tip of the bill found in ducks and geese.n. A nail, claw, or hoof of any animal.n. A measure of length, about half an inch. In anatomy: The human lacrymal bone: so called because it resembles the human finger-nail: more fully called os unguis.n. The hippocampus minor, or calcar, of the brain. Also unguis avis, unguis Halleri.n. In entomology, one of the curved claws at the extremity of an insect's tarsus.n. In botany, the claw or lower contracted part of some petals, by which they are attached to the receptacle, as in the pink, the mustard, Cleome, etc. It is analogous to the petiole of a leaf. Also ungula. See cut under claw.