- withdrawal of the penis in sexual intercourse so that ejaculation takes place outside the vagina; coitus interruptus.
- another name for masturbation, coitus interruptus
n.“masturbation,” also “coitus interruptus,” 1727, from Onan, son of Judah (Gen. xxxviii:9), who spilled his seed on the ground rather than impregnate his dead brother’s wife: “And Onan knew that the seed should not be his; and it came to pass, when he went in unto his brother’s wife, that he spilled it on the ground, lest that he should give seed to his brother.” The moral of this verse was redirected by those who sought to suppress masturbation. n.
- coitus interruptus