Hardcore band, unconvincing here, finally shows bite (4)
I believe the answer is:
edge
'bite' is the definition.
(I've seen this before)
'hardcore band unconvincing here finally' is the wordplay.
'finally' says to take the final letters.
The final letters of 'hardcore band unconvincing here' are 'EDGE'.
'shows' is the link.
(Other definitions for edge that I've seen before include "Brim" , "Move carefully; limit" , "Sharp ridge" , "marginal advantage" , "Move slowly" .)