Jackhammer:
1. jackhammer
1. A sexual manuver of constant re-penetration; basically taking the **** in an out of the vagina (or anus) repeatedly, in a 'jackhammer'-like motion / or jacking off on a chick's face from a really short distance away
2. Jackhammer
A sexual position similar to Doggystyle, but you lift her legs off the ground. Then you stand, forcing her body to be arranged at a downward angle. It is named for the resemblence of a construction worker pounding away on a jackhammer
Jim: Can we go fr Doggy tonight?
Alicia: Doggy is getting boring, lets mix it up, JACKHAMMER ME!!
Jim: Who's your daddy bitch
3. Jackhammer
the sexual act of a man repeatitively penetrating a woman's entry hole with rapid up and down movements similiar to that of a jackhammer
Alex jackhammered Jody so hard that she could not walk the next day.
It's a nickname that an old gf gave to me