Left omen about fruit (5)
I believe the answer is:
lemon
'fruit' is the definition.
(lemon is a kind of fruit)
'left omen about' is the wordplay.
'left' becomes 'l' (common abbreviation).
'about' indicates an anagram.
'omen' is an anagram of 'emon'.
'l'+'emon'='LEMON'
(Other definitions for lemon that I've seen before include "Dab" , "very different from peach?" , "Useless object" , "Unhelpful answer" , "certainly not a plum!" .)