Knife part (5)
I believe the answer is:
'knife part' is the definition.
('blade' is part of 'knife')
This is all the clue.
(Other definitions for blade that I've seen before include "Cutting edge" , "Runner on an ice-skate" , "Flat part of an oar" , "A knife, or a dashing fellow" , "Young chap, dashing" .)