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1.
Convex curvature of the spine, making the ass stick out in a feminine way, thus creating a potbelly in the front.
Balding Curt Moyer of Susquehanna University has one hell of a swayback.
by Melons October 24, 2005
 
2.
What people said I have. I never knew what it was 'til I read the first definition. Apparently it's a good thing :)
So I have a swayback...that's why it looks like my stomach and a*** stick out!
by littleblackdress35 August 12, 2008
 
3.
a chick who has no ass what so ever
damn jenny i like your outfit but your {swayback] just ruined it
by Mz.GOODIE June 19, 2009