Onanism refers to ejaculation that occurs outside of the vagina. It is often used as a term for male masturbation.
More About Onanism
The term onanism was derived from the biblical story of Onan, who wasted semen by ejaculating outside of the vagina. Onanism was coined to refer to ejaculation outside of the vagina, also referred to as coitus interruptus. This can refer to both male masturbation or intercourse where the withdrawl or pull-out method is used.