look up any word, like blumpkin:
 
1.
The act of inserting one's thumb into another's anus, repeatedly.
"Suzie squealed like a pig in heat whilst I was fonzing her last night."
by Grebby Boeby July 13, 2005
 
2.
The act of a girl getting fingered and being pleased by different men on drunk nights but, remembering the pleasure the next day.
"Are we drinking tonight?
-Yeah definitely! I wonder who's fonzing me tonight :)"
by DrewidMadison March 09, 2010