When your dick is partial chub and you grasp the lower shaft, forcing all the blood into the penal tip.
Tom: "Hey Gabe what did you do last night?"
Gabe: "Not much. My mom came in and caught me girthing though."
Gabe: "Not much. My mom came in and caught me girthing though."
by Deputy Dingus April 15, 2015
The act of getting on the Zero Gravity fair ride pantsless, and throwing a dildo up into the air while at the highest point. So that it comes down with the force of Thor's hammer into the vagina.
by Deputy Dingus September 03, 2015