n. In anatomy, a foss, pit, depression, or hollow of some kind in any structure, specified by a qualifying term.n. In zoology, a deep pit or depression in the hard integument of an animal, often opening into the interior cavity of the body and serving for the point of attachment of an organ: as, the antennary fossa of an insect.n. See the adjectives.n. A depressed space between the posterior commissure of the vulva and the fourchette.n. The surface by which the temporal bone articulates with the lower jaw; improperly extended in human anatomy to include the whole of the smooth surface of the vaginal process behind the Glaserian fissure, in relation with the parotid gland, and not concerned in the temporomaxillary articulation. See cut under skull.n. The innominate fossa of the outer ear; the groove between the helix and the antihelix; the fossa of the helix. See second cut under ear.n. In zoology, a genus of Madagascan viverrine quadrupeds, allied to the genets.n. [lowercase] The species of this genus, formerly called Genetta fossa.n. The pit of the stomach.n. A depression in the hyaloid membrane of the eye on a level with the entrance of the optic nerve.n. See supraclaticular.n. The depression between the sternal and the clavicular origins of the sternomastoid muscle.