A term used by those 2 out of 3 lol cats that believe in Ceiling Cat and do not believe in Christianity's "God", therefore they do not use the term "OMG" a.k.a "Oh My God".
"OMCCWTFBBQ! A Capshun!" said the lol cat on icanhascheezburger.com
The upper portion of the inside of the mouth. More commonly and incorrectly referred to as the "roof" of the mouth. This doesn't make sense because it's inside, like a ceiling, not outside, like a roof. The scalp and hair are the roof of your head, and your mouth has a ceiling.
Dan: "No thanks. Last night, I made a pizza in the oven, and like an idiot, I bit into a piece right away. The hot cheese burned the ceiling of my mouth. It hurts. I need to eat apple sauce for a few days".