1 definition by xchgsjhkd
A person with a giant back, but an incredibly small penis. To make up for insecurities resulting from a case of babydick, a fat back will overcompensate and take advantage of any oppurtunity to brag about his or her hugeness, back or otherwise.
When everyone started talking about their penises, Mike the Fat Back quickly changed the conversation: "I'm the only one who can get this tattoo 'cause my back's so big"
by xchgsjhkd November 24, 2010