GNU Collaborative International Dictionary of English

Found one definition

1.       
   { Jambes , Jambeux , } n. pl. [From  F. jambe a leg: cf. OF. jambiere. See Jamb, n.] (Ancient Armor) In the Middle Ages, armor for the legs below the knees, usually having front and back pieces; called also greaves. [Written also giambeux.]
   Chaucer.
   
   1913 Webster