nausea vs queasiness

nausea and queasiness both are nouns.

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

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

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

nausea (noun)	queasiness (noun)
disgust so strong it makes you feel sick	inability to rest or relax or be still
the state that precedes vomiting	a mild state of nausea