Hedgehog is very nice for the most part (5)
I believe the answer is:
sonic
'hedgehog' is the definition.
(I've seen this before)
'very nice for the most part' is the wordplay.
'very' becomes 'so' (I've seen this in other clues).
'for the most part' means to remove the last letter.
'nice' with its last letter taken away is 'nic'.
'so'+'nic'='SONIC'
'is' acts as a link.
(Other definitions for sonic that I've seen before include "Kind of boom" , "seven hundred and forty three mph!" , "Sort of boom" , "Using waves" , "Relating to sound waves" .)