stomach vs bear up

stomach is a noun but bear up is not a noun.

Word	Noun	Adjective	Verb	Adverb
stomach	Yes	No	Yes	No
bear up	No	No	Yes	No

As verbs, bear up is a hyponym of stomach; that is, bear up is a word with a more specific, narrower meaning than stomach:

stomach (noun)	bear up (noun)
an enlarged and muscular saclike organ of the alimentary canal; the principal organ of digestion
the region of the body of a vertebrate between the thorax and the pelvis
an appetite for food
an inclination or liking for things involving conflict or difficulty or unpleasantness

stomach (verb)	bear up (verb)
put up with something or somebody unpleasant	endure cheerfully
bear to eat