1.  fossa(n = noun.shape) pit - a concavity in a surface (especially an anatomical depression); Array
is a kind of bodily cavity, cavity, cavum, concave shape, concavity, incurvation, incurvature
has particulars: glenoid cavity, glenoid fossa, glenoid fossa, mandibular fossa, epigastric fossa, pit of the stomach

2.  fossa(n = noun.animal) genus fossa - monotypic genus of Madagascar civets closely related to palm civets; Array
is a kind of mammal genus
is a member of family viverridae, family viverrinae, viverridae, viverrinae

3.  fossa(n = noun.animal) cryptoprocta ferox, fossa cat - largest carnivore of Madagascar; intermediate in some respects between cats and civets; Array
is a kind of viverrine, viverrine mammal

   A pit, groove, cavity, or depression, of greater or less depth; as, the temporal fossa on the side of the skull; the nasal fossæ containing the nostrils in most birds. [1913 Webster]

fossa, n. (pl. fossae) Anat. a shallow depression or cavity.

Etymology:
L, = ditch, fem. past part. of fodere dig

axillary fossa, epigastric fossa, fossa cat, fossa fossa, genus fossa, glenoid fossa, mandibular fossa