duck-arsed

adjective2

1. •
   (slang, vulgar) Having or pertaining to broad hips and large, bulging buttocks.

   • All the girls, with the exception of May Callan, were squat, and as the country phrase had it—"duck-arsed." They were made for work, for breeding. — 1949
2. •
   (UK, informal) Having or pertaining to a hairstyle of the type called a duck's arse.