Top Definition
when having sex with a female as the man is about to ejaculate he removes his member and smacks it with incredible force using his penis as a hammer on the women's stomach or ass blowing his load all over her.
while steve was pounding on jills vag he surprised her with a quick hammerjack!
by ap12387 April 07, 2010
1 more definition
Masturbating without lotion
Tom: " Do you Gillette "
Fred: "No I Hammer Jack "
by FFBurger1 April 12, 2012

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from daily@urbandictionary.com. We'll never spam you.

×