The flaps of fabric on either exterior side of a zipper. Most commonly found on cheap wind breaker jackets and frequently get caught in the upward and downward zip causing it to jam.
The subsequent zipper jam is usually followed by swearing in frustration and potentially the break of the zipper.
My zipper labia on my jacket are way too big, they always get caught in my zipper.

Damn zipper labia, got caught again, they're flappin' around like beef curtains!
by AJ Parnayyyyl October 19, 2011
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