blade

: the flat sharp part of a weapon or tool that is used for cutting — see picture at carpentry; see also razor blade, switchblade

: one of the flat spinning parts that are used on some machines to push air or water

: the wide flat part of an oar or paddle

: the sharp metal piece on the bottom of an ice skate — see picture at skate

: a single piece of grass or a similar plant

a  : sword 1

b  : swordsman