The term given to the large butt like lump near the vagina when overweight (usually Greek) women attempt to hide their stomach buy sticking it into their pants. this gives them the appearance of having two butts, or a 'butt cunt'.
Can also be used as a derogatory term for anything (or anyone) you are even the slightest bit annoyed at.
example 1 - "hey have you noticed dianne lately?"
- "yeah dude, she's developed a monster 'butt cunt'"
- "she just doesnt care anymore"
example 2 - "hey leigh, did you remember to get the doritos?"