To greet someone by approaching them, and giving them a backhanded slap across the face.
Give him an irish handshake and he'll shutup
a greeting given to a male adversary consisting of grabbing him by the balls and squeezing as hard as possible until he doubles over in pain, then headbutting him in the bridge of the nose.
"If you think he's too big to take down otherwise, give him the old Irish Handshake, he'll be on the ground bleeding before he knows what hit him."
When a guy is throwing up and receiving a hand job from a girl at the same time.
"Hey man, you just puked all over the car and that ho gave you a irish handshake"
When a guy is so drunk that he starts puking while receiving a handjob.
Guy 1:"dude how drunk were you last night?"
Guy 2:"Drunk enough to get a Irish Handshake"
Guy 1:"Sick!! From who?"
Guy 2:"I was so drunk I don't remember her name"
Receiving a handjob from a girl while puking from being too drunk.
"OMG, you just puked all over the floor and this girl just gave you a irish handshake....what a whore"
When a guy vomits and gets a handjob at the same time by a girl.
"Boy you were sick, did you just get an irish handshake behind the barn?"
When a guy is throwing up and receiving a hand job from a girl at the same time.
"Hey man, you just puked all over the car and that ho gave you a irish handshake"