masturbation vs autoerotism

masturbation and autoerotism both are nouns.

Word	Noun	Adjective	Verb	Adverb
masturbation	Yes	No	No	No
autoerotism	Yes	No	No	No

As nouns, autoerotism is a hypernym of masturbation; that is, autoerotism is a word with a broader meaning than masturbation:

masturbation: manual stimulation of the genital organs (of yourself or another) for sexual pleasure
autoerotism: using your own body as a sexual object

Other hypernyms of masturbation include autoeroticism.

masturbation (noun)	autoerotism (noun)
manual stimulation of the genital organs (of yourself or another) for sexual pleasure	using your own body as a sexual object