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2.
A term of utmost hatred used to define someone with a weight problem; this term should not be used in reference to someone who could kick your ass, only in situations where the fatass is totally immobile or just a pussy.
Hateful Person: Put those Cheetos down you fucking fatback
Fatback: Dude, I'd hit you if I could get up off this bed.
Hateful Person: Yeah, you're fuckin-a right you grotesque fatback mother-fucker.
by Raagers October 18, 2004
 
1.
The flab that hangs over and around the back of a fat woman's bra. Also rolls of fat that incorporate the undrarms and shoulders of said fat women.
have you seen that chick eat? No wonder she's got a ton of fat back on her.
by jotthedot March 28, 2006
 
3.
Late 60's, early 70's style funk rhythm guitar, often accomplished using a wah pedal and 9th chords. Listen to the theme of "Shaft."
That dude's layin down some bad-ass fatback.
by Andy December 26, 2003
 
4.
A person that is so fat or overweight that they got rolls on their back. the type you would usually see on a persons stomach.
Yeah man, I saw Denise at the Hilton Party last night, she changed man. She fatback now.

Yo fatback ass

Damn, shawty been fatback since grade school

Her ass fatbacking.
by Yayo Da Don June 03, 2011
 
5.
The extra amount of skin (fat) that droops over the back and sometimes sides of girls bras. Usually happens when they are too fat or the bra is too small.
"Man did you see that new girl in math? That Hollister shirt so showed off her fatback!"
by Scotty Wilson March 24, 2008
 
6.
A layer of buttery cheese commonly found on a sorostitute's back, just above her waist that usually shows signs of dunlap disease and may or may not be accompanied by a large stripper tattoo. This type of fatback is mostly caused from drinking beer and eating large pizzas all by themselves. Possibly a major portion of their freshman fifteen.
Damn, that sorostitute has a serious case of the fatback!!
by JRatt June 17, 2005
 
7.
A referal of a females backside or booty, appealing to the opposite sex, which is man. (No Males should have a fatback. Females are strickly forbidden to use this world unless your gay).
Man, the fatback on that female can cover the whole solar system.
by neiman July 06, 2004