Bit of a blade, this fellow (3)
I believe the answer is:
lad
'fellow' is the definition.
('lad' can be a synonym of 'fellow')
'bit of a blade this' is the wordplay.
'bit of' indicates the answer is hidden within the clue.
'LAD' is hidden in the letters of 'blade this'.
(Other definitions for lad that I've seen before include "Stable employee" , "Chap, fellow" , "Boy, familiar" , "Young fellow" , "Son" .)