Pignus | Webster's Dictionary of the English Language

pignus
pignus, ŏris and ĕris (old form in plur.: pignosa pignora eodem modo quo valesii, auselii ... diceba...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
pignus
pīgnus oris and eris, n PAC-, a pledge, gage, pawn, security, guaranty : ager oppositus est pignor...

An Elementary Latin Dictionary