1 definition by Holycrapthisisawesome

A woman in a bathing suit who has an extra flap of skin over her ass. It is most disturbing when she bends over. No one knows how it got there, but there it is, a flap of skin right over her ass.
John: Did you see that woman's ass?
Sara: Holy cow, she has a flap ass.
by Holycrapthisisawesome June 21, 2007
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