Fruit of the melon variety (5)
I believe the answer is:
lemon
'fruit' is the definition.
(I know that lemon is a type of citrus fruit)
'melon variety' is the wordplay.
'variety' is an anagram indicator.
'melon' anagrammed gives 'LEMON'.
'of the' acts as a link.
(Other definitions for lemon that I've seen before include "definitely not a peach" , "Fruit high in vitamin C" , "leaving bitter taste?" , "Unhelpful answer" , "Tone" .)