This is a Latin word meaning a trench, a ditch, or an excavation. It arises from the Latine term [fodere] meaning "to dig". The plural form for "fossa" is "fossae".

There are many fossae listed in human anatomy, here are some of them:

• fossa scaphoides: found in the pinna
• fossa ovalis: found in the wall of the right atrium
• fossa triangularis: found in the pinna
• ischioanal fossa: a triangular fossa found in the perineum, inferior to the pelvic diaphragm and superior to the urogenital diaphragm, etc.