1. Manual stimulation of the genital organs (of yourself or another) for sexual pleasure
   "onanism is a common form of sexual expression";
   - masturbation
    
2. A method of birth control in which coitus is initiated but the penis is deliberately withdrawn before ejaculation
   "They relied on onanism, despite its unreliability as a contraceptive method";
   - coitus interruptus, withdrawal method, withdrawal, pulling out

Derived forms: onanisms

Type of: autoeroticism, autoerotism, birth control, birth prevention, family planning

Encyclopedia: Onanism