Dictionary.net

The hind-leg of a horse: a stick crooked like a horse's leg, used by butchers for suspending animals while dressing them. "Spied two of them hung out at a stall, with a gambril thrust from shoulder to shoulder, like a sheep that was new-flayed."-Chapman..

To tie or hang up by means of a gambril thrust through the legs. "I'll … carry you gambrell'd like a mutton."-Beau & Fl.