The super-heated cheese stuffing of any number of baked or fried foods when freshly done. Typically applied when the food is not allowed to cool for long enough.
I bit into my pizza bite right out of the microwave and the lava cheese burned the hell out of my tongue.
by Astexix December 8, 2010
When your mouth is so dehydrated that cheese becomes like lava because you cannot swallow it due to the massive amount of drugs in your system.
by Party Crew March 30, 2005