thesis vs premiss

thesis and premiss both are nouns.

Word	Noun	Adjective	Verb	Adverb
thesis	Yes	No	No	No
premiss	Yes	No	Yes	No

As nouns, premiss is a hypernym of thesis; that is, premiss is a word with a broader meaning than thesis:

thesis: an unproved statement put forward as a premise in an argument
premiss: a statement that is assumed to be true and from which a conclusion can be drawn

Other hypernyms of thesis include assumption, premise.

thesis (noun)	premiss (noun)
an unproved statement put forward as a premise in an argument	a statement that is assumed to be true and from which a conclusion can be drawn
a treatise advancing a new point of view resulting from research; usually a requirement for an advanced academic degree

thesis (verb)	premiss (verb)
	take something as preexisting and given