A love apple (6)
I believe the answer is:
tomato
'a love apple' is the definition.
(I know that love apple can be written as tomato)
This is the entire clue.
(Other definitions for tomato that I've seen before include "Type of sauce" , "Love apple (or "beef" fruit?)" , "It's also known as a love apple" , "A motto turned out to be fruit or veg" , "Red fruit eaten as veg" .)