Fighting men cut by a blade (3)
I believe the answer is:
oar
'blade' is the definition.
(blade is the word for oar in competitive rowing)
'fighting men cut by a' is the wordplay.
'fighting men' becomes 'or' (military abbreviation for Other Ranks).
'cut by' means one lot of letters goes inside another (some letters cut into others).
'or' going around 'a' is 'OAR'.
(Other definitions for oar that I've seen before include "Rowing device" , "Bladed implement" , "that may be feathered?" , "Rowing implement" , "Bladed pole" .)