stoma vs orifice

stoma and orifice both are nouns.

Word	Noun	Adjective	Verb	Adverb
stoma	Yes	No	No	No
orifice	Yes	No	No	No

As nouns, orifice is a hypernym of stoma; that is, orifice is a word with a broader meaning than stoma:

stoma: a mouth or mouthlike opening (especially one created by surgery on the surface of the body to create an opening to an internal organ)
orifice: an aperture or hole that opens into a bodily cavity

Other hypernyms of stoma include opening, porta.

stoma (noun)	orifice (noun)
a mouth or mouthlike opening (especially one created by surgery on the surface of the body to create an opening to an internal organ)	an aperture or hole that opens into a bodily cavity
a minute epidermal pore in a leaf or stem through which gases and water vapor can pass