A dirty cardigan is the thick coating of plaque that you find after you wake from a hard night of partying. Often associated with the infamous "dragon's breath," the dirty cardigan is a semi-considerate way of stating that you need to brush your teeth and stat!
"Man Ramone, I blacked out last night and woke up wearing a dirty cardigan! Can I borrow your toothbrush, man?
by MotananZ406 March 22, 2011