IPA: /ˌɔːtəʊɪˈrɒtɪsɪzm/
KK: /ˌɔːtəʊɪˈrɒtɪsɪzm/
The act of achieving sexual pleasure by stimulating one's own body without the involvement of another person.
He explored his feelings of autoeroticism in a private setting.
Autoeroticism is formed from "auto-" (meaning self) and "eroticism" (from Greek "erōtikos", meaning of or pertaining to love or sexual desire). The term describes sexual arousal or stimulation that is derived from oneself.
Think of 'self' ('auto-') and 'sexual desire' ('eroticism') to remember that autoeroticism refers to sexual arousal that comes from oneself.