onanism

noun2

1. •
   (formal, old-fashioned) Masturbation.

   • This photograph was far superior. A nude woman was sitting on the edge of a desk next to a globe of the world. The suggested onanism with the piece of chalk intrigued Ignatius. — 1963
2. •
   (formal, old-fashioned) Ejaculating outside the vagina during intercourse; (the performing of) coitus interruptus.