look up any word, like bukkake:
 
1.
It is a form of Slang for Vagina
her cooch smells like a tuna fish sandwich
by tainted Bebop November 09, 2006
 
2.
(n)

The act of rubbing two unwashed vaginas together in a sexual manner.
Olga and Bethany were horny even though their water was shut off, so they decided to Tuna Fish Sandwich eachother.
by One Twenty7 January 22, 2011
 
3.
A Rim Job
She gave him a tun fish sandwich instead of a blow job
by Ozzy October 03, 2003