An Assjammer is a person who loves jammin that thing up those honeybuns a little too much. People will mostly associate assjammers with gay people or pedophiles.
"I wouldn't trust that guy over there, he's an assjammer!" said the bartender.
An "assgabbler" is a person who continually gets pushed around by his bandmates, gets used and abused, lets others take credit for his songwriting, gets teased in front of hotties, and continues to take it because "everyone else in town only likes techno."