thesis vs treatise

thesis and treatise both are nouns.

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

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

thesis: a treatise advancing a new point of view resulting from research; usually a requirement for an advanced academic degree
treatise: a formal exposition

thesis (noun)	treatise (noun)
an unproved statement put forward as a premise in an argument	a formal exposition
a treatise advancing a new point of view resulting from research; usually a requirement for an advanced academic degree