The female version of a Dutch oven. When a woman with a fishy smelling private area, whether she knows it or not, puts a partners head under the covers in a bed for oral pleasures.
Man, I was messing around with this girl last night, and when I lifted up the covers to go down she gave me a tuna melt.
by Chaos31 April 01, 2012
An unclean vagina. (derived from the combination of the joke: "Why don't you eat out your girlfriend in the Morning? Ever open up a grilled cheese sandwich?" and the famous fish-vagina connection)
I'm sorry baby, but I don't like this tunamelt, do you have peach cobbler instead?
by Gunt January 05, 2003