Enjoy nuts greatly (4,5)
I believe the answer is:
like crazy
'greatly' is the definition.
'enjoy nuts' is the wordplay.
'enjoy' becomes 'like' (I've seen this before).
'nuts' becomes 'crazy'.
'like'+'crazy'='LIKE CRAZY'
(Other definitions for like crazy that I've seen before include "great enthusiasm" , "Furiously" , "Very much" .)