Struggle with Greek fruit (7)
I believe the answer is:
grapple
'struggle with' is the definition.
(I've seen this before)
'greek fruit' is the wordplay.
'greek' becomes 'gr' (abbreviation for Greek).
'fruit' becomes 'apple' (apple is a kind of fruit).
'gr'+'apple'='GRAPPLE'
(Other definitions for grapple that I've seen before include "Engage in a close fight" , "Fight hand-to-hand" , "struggle" , "Engage in close fighting" , "Attempt to get hold of, or seize" .)