Top Definition
When the scrotum becomes so tight that it pushes up the flaccid penis, causing it to resemble a semi.

May occur under conditions such as cold temperature, strenuous physical activity, or extreme anxiousness.
Josh: Dude your dick is sticking out in your sweatpants, do you have a semi?

Drew: Nah bro, I've got push-up balls.
by Manmess November 23, 2013

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from daily@urbandictionary.com. We'll never spam you.

×