The generous spread of chubby fat on the body parts that are not covered with clothing, like in the neck area or calfs/thighs or triceps. Usually associated with obese people. A muffin top can be considered a part of chubbery.
Example : His dad got some serious chubbery surrounding his face. They better work on his diet!
A grave chubber is a illustrative phrase used to insinuate that a certain occurrence or thing would please a person who is deceased. It can be considered the opposite of causing someone to roll over in their grave.