A Jill is an unspayed (fertile) female ferret. Spayed female ferrets are called sprites, unneutered males are called hobs, neutered males are called hoblets and young are called kits.
a jill strap protects the lower belly and pelvic bone. It is the equivalent of a male's cup. (jock strap) jock strap is A garment made of stretchy cotton intended primarily to embarass teenaged boys...