nauseous vs sickish

nauseous and sickish both are adjectives.

Word	Noun	Adjective	Verb	Adverb
nauseous	No	Yes	No	No
sickish	No	Yes	No	No

As adjectives, nauseous and sickish are synonyms defined as:

Other synonyms of nauseous include nauseated, queasy, sick.

nauseous (adjective)	sickish (adjective)
feeling nausea; feeling about to vomit	feeling nausea; feeling about to vomit
causing or able to cause nausea