French fly, or waist stay, for trousers/shorts
Added Apr 1, 2012
The French fly for trousers is a hidden extra closure with an inside button tab attached to an internal belt or waist stay. its function is to allow the flap of the fly to sit down smooth and flat in a more relaxed way by taking any strain off the top of the zip.
It is seen in better quality men's dress or suit trousers, and occasionally in womenswear (but not often enough)
Zip, fabric for waist stay (firm, densely woven and non-stretchable), button