Novice misconstrued omen as fruit (5)
I believe the answer is:
Here is my best explanation:
'fruit' is the definition.
(lemon is a kind of fruit)
'novice misconstrued omen' is the wordplay.
'novice' becomes 'l' (abbreviation for Learner e.g. on UK cars).
'misconstrued' indicates anagramming the letters.
'omen' with letters rearranged gives 'emon'.
'as' acts as a link.