The small amount of wet shit that ends up in male underwear after urinating, usually caused by farting or a relaxed anal sphincter.
Mom: "Goddamit it Sol, look at this blow by in your underwear!"
Son: "Oh fuck you, just do the laundry and shut up."
Mom: "I swear Sol, sometimes I don't think you're my son, or Jewish, or enrolled at Penn."
Son: "Suck my soulja boy, Mama."
A smallbirthday cake purchased in additional to the regular cake. This cake is used to absorb the spittle blown when the celebrant blows out the candles, leaving the actual birthday cake uncontaminated so that all guests may enjoy it.
We had better get a blow cake for Uncle Lester's birthday so that he doesn't ruin everyone's cake like last year.
The legendary, and most deadliest weapon to ever exist. Only the fattest and mightiest of the Akimichi may wield this ancient power. One shot from this, and an entire planet could be destroyed in an instant. How this works, is that the chosen weilder has a special type of fart gas, and when released, it can cause mass destruction. Basically, it is like a nuclear bomb that can be shot out of your booty, except it is 1 trillion times stronger.
Breaking News: A castastrophic Blow Horn Type 5 has destroyed planet Moksus.