Top definition
The man custard that shoots from the penis when rubbing one out.
"That chick is so hot, when I get home I'm gonna pop off some knuckle babies. When doing so, she will tell me I am great, and I will believe her."
by tommyboy79 April 06, 2006
Happy St. Patties Day!
n. Male ejaculate resulting from masturbation
Lindsay Lohan posed naked for Playboy, and I gave birth to a knuckle baby.
by peo May 24, 2008
Happy St. Patties Day!
n. knucklebabies is the outcome a male gets after he roughs up his suspect (masterbates) and dosent release his sperm into a sock or something and it is all over the back of his hand.
I got home late lastnight and my wife was asleep,so i went to the computer and racked out a batch of knucklebabies.
by richard bellamy March 08, 2008
Happy St. Patties Day!
Sperm or semen, especially when induced by masturbation.
"Yo Scooter, what's up with your petrified Kleenex?"

"It's nothin' dude, just my knucklebabies from rubbing one out earlier today."
by dandruffy July 21, 2008
Happy St. Patties Day!