When a girl is giving a handjob and starts to pound so hard you think your balls will go into your asshole.
by Rajalec October 14, 2004

what you do is a cricket on 1 hand so the other hand behind your back or something and then bounce in a circle.
a jackhammer look impossible
by blazed December 9, 2004

Commonly known as Hansen, Hardcore, or Destructor. Is tricky and requires you to get on top. Characteristics include a rhythmic pounding and a peculiar knowledge of aquatic life.
1. When going to the bars, Hansen likes to turn on the charms of the Jackhammer.
2. The Jackhammer is tricky like that, sometimes you gotta climb on top and ride it out
2. The Jackhammer is tricky like that, sometimes you gotta climb on top and ride it out
by Goose81 July 18, 2003

The heavy weapon of the New Conglomerate in the PC game Planetside. The Jackhammer is a three-barrled fast firing shotgun that is commonly used as a frontal assualt weapon.
by DarkFusion April 14, 2004

when you're fisting a girl in the vagina and anus at the same time. (i.e. like you're using a jackhammer)
JB: dude, where we're you last night?
Dani: jackhammering yer mam lol
Dani: i got in there right up to the elbows
Dani: jackhammering yer mam lol
Dani: i got in there right up to the elbows
by unquestioned_answers September 26, 2006

by augdizl February 3, 2004

He did a jackhammer last night
by Coopachup November 28, 2018
