When you punch a girl so hard in the vagina that it turns purple and she cries.
That ugly bitch tried to rape me so I gave her a purple onion.
by mitsukosouma July 04, 2011
the female equivalent to blue balls (i.e. unfulfilled sexual pleasure from or after being sexually teased).
That hot guy gave me such a purple onion when he bent over.
by Andy7 August 16, 2007