Like bear furs in enormous boxes (6)
I believe the answer is:
ursine
'like bear' is the definition.
(I know this)
'furs in enormous boxes' is the wordplay.
'boxes' indicates a hidden word (to box can mean to contain).
'URSINE' can be found hidden inside 'furs in enormous'.
(Other definitions for ursine that I've seen before include "Bearlike" , "like a character in 14 across [=>BEAR]" , "Relating to bears" , "Describing Pooh or Yogi?" , "Like Paddington" .)