nausea vs squeamishness

nausea and squeamishness both are nouns.

Word	Noun	Adjective	Verb	Adverb
nausea	Yes	No	No	No
squeamishness	Yes	No	No	No

As nouns, squeamishness is a hyponym of nausea; that is, squeamishness is a word with a more specific, narrower meaning than nausea:

Other hyponyms of nausea include kinetosis, motion sickness, morning sickness, qualm, queasiness.

nausea (noun)	squeamishness (noun)
disgust so strong it makes you feel sick	the trait of being excessively fastidious and easily shocked
the state that precedes vomiting	a mild state of nausea