Similar to its close cousin the Chub
. The chub is a semi flaccid semi erect penis with a 90 degree angle. A chub occurs when you see a girl from behind who you think is extremely hot then you see her face and relies she is hideous.
I saw that girl pass by at lunch before and almost popped a boner until she turned around and i saw her face. I just ended up with a hanging shub instead.