hypnosis vs mental state

hypnosis and mental state both are nouns.

Word	Noun	Adjective	Verb	Adverb
hypnosis	Yes	No	No	No
mental state	Yes	No	No	No

As nouns, mental state is a hypernym of hypnosis; that is, mental state is a word with a broader meaning than hypnosis:

hypnosis: a state that resembles sleep but that is induced by suggestion
mental state: (psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic

Other hypernyms of hypnosis include mental condition, psychological condition, psychological state.

hypnosis (noun)	mental state (noun)
a state that resembles sleep but that is induced by suggestion	(psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic