Fruit eaten with grin spreading (9)
I believe the answer is:
tangerine
'fruit' is the definition.
(tangerine is a kind of fruit)
'eaten with grin spreading' is the wordplay.
'with' says to put letters next to each other.
'spreading' indicates an anagram.
'eaten' put after 'grin' is 'grineaten'.
'grineaten' is an anagram of 'TANGERINE'.
(Other definitions for tangerine that I've seen before include "fruit product" , "Green tan I change into orange" , "Small orange" , "shade" , "something juicy being given to press" .)