onanism
noun
onan·ism ˈō-nə-ˌni-zəm 
1
: masturbation
2
: coitus interruptus
3
: self-gratification
the kind of intellectual onanism to which he was dedicated
Esther P. Shiverick
Esther P. Shiverick onanistic
ˌō-nə-ˈni-stik
adjective 
Word History
Etymology
probably from New Latin onanismus, from Onan, son of Judah (Genesis 38:9)
First Known Use
1718, in the meaning defined at sense 1
Medical Definition
onanism
noun
onan·ism ˈō-nə-ˌniz-əm
1
: masturbation
2
: coitus interruptus