Top Definition
A reference to a woman's backside - specifically a really well-formed one. So called because, as we all know, crossing a mule and an onion results in "an ass that'll bring tears to your eyes".
"Damn, look at the mule onion on that one!"
by Heathen 2.0 April 28, 2008
5 Words related to Mule Onion

Free Daily Email

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

Emails are sent from We'll never spam you.