I.the navel, Lat. umbilicus, Il., Hdt., etc.
II.anything central (like a navel):
1.the knob or boss in the middle of the shield, Lat. umbo, Il.
2.a button or knob on the horse's yoke to fasten the reins to, id=Il.
3.in pl. the knobs at each end of the stick round which books were rolled, Lat. umbilici, Luc.