"masturbation," also "coitus interruptus," 1727, from Onan, name of the son of Judah (Genesis 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 point of the verse was redirected by those who sought to suppress masturbation. Related: Onanist; onanistic.