look up any word, like blumpkin:
 
1.
When a fat bitches back is more shapely than her ass, and her body resembles an apple placed on top of a hot dog. Also known as muffin top, or nasitall (no ass at all).
"that chicks ass is concave. no, wait, that's just back ass."
 
2.
Denoting a huge bitches ass that has encroached on her back, thus confusing whether or not its her back rolls or a fucking huge ass.
"Wow dude - is that a Backass?"

"Benefit of the doubt there."
by Zagash September 03, 2008
 
3.
When someone is so fat that when they are bent over and you see their back, the fat it makes an ass shape.
When Tubby bent over he had a huge backass
by msmeanie February 03, 2010
 
4.
Categorized as a grinding Move, when the male bends the female over and thrust's his waist and pelvis into her behind.

*Note This is With Clothes on, without clothes would be known as Backshots*

(Origin) First seen in Be-ezzy in the year 2007 by

"K****** Offical.")
(Example):
"Yo K****** shes a Kitty Yute allow her, then Ali will give her a BACKASS. "Quoted by S*** A****"

(Explanation):
In this case it means Ali will grab Kitty Yute's waist and bend her over, then thrust his hips into her behind (with clothes on also similar to grinding)
by JayCity112 June 01, 2010
 
5.
American for backarse which is itself a term that describes the remotest and most isolated part of any area. Since this is the American version it has a lower threshold for remoteness. A city containing a few million people could still be described as a backass by most Americans if the city is outside the USA
Ireland? Isn't that in the backass of Yurop somewhere?

No people, no roads, no electricity, no signal on my cell phone; that must mean I'm in the backass of nowhere
by Dankoozy September 07, 2008
 
6.
An unusually high positioned rear end, that in some extreme cases might allow someone to wipe their ass from the front side, over their shoulder.
backarse
Dude, check out the backass on that broad!
by scooterguy June 09, 2005
 
7.
To perform a task in an illogical fashion.
Instead of Mary signalling before turning into the parking lot, she decided to be back ass and signal after completing the turn.
by signull July 04, 2006