epigastric fossa vs pit of the stomach

epigastric fossa and pit of the stomach both are nouns.

Word	Noun	Adjective	Verb	Adverb
epigastric fossa	Yes	No	No	No
pit of the stomach	Yes	No	No	No

As nouns, epigastric fossa and pit of the stomach are synonyms defined as:

epigastric fossa and pit of the stomach: a slight depression in the midline just below the sternum (where a blow can affect the solar plexus)

epigastric fossa (noun)	pit of the stomach (noun)
a slight depression in the midline just below the sternum (where a blow can affect the solar plexus)	a slight depression in the midline just below the sternum (where a blow can affect the solar plexus)