Fruit Thomas endlessly ate with love (6)
I believe the answer is:
tomato
'fruit' is the definition.
(type of fruit)
'thomas endlessly ate with love' is the wordplay.
'thomas' becomes 'tom'.
'endlessly' means to remove the last letter.
'with' says to put letters next to each other.
'love' becomes 'o' (love means zero in tennis).
'ate' with its final letter taken off is 'at'.
'tom'+'at'+'o'='TOMATO'
(Other definitions for tomato that I've seen before include "Pulpy fruit eaten as vegetable" , "A motto turned out to be fruit or veg" , "Love apple (archaic)" , "A motto, oddly, for this fruit" , "Also called the love apple" .)