Natural love must come before caring about ... (7)
I believe the answer is:
organic
'natural' is the definition.
(similar in meaning)
'love must come before caring about' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'must come before' is a charade indicator (letters next to each other).
'about' indicates anagramming the letters.
'caring' with letters rearranged gives 'rganic'.
'o'+'rganic'='ORGANIC'
(Other definitions for organic that I've seen before include "The sort of crop" , "Grown without chemical fertilisers" , "Gin, Cora? (Anag)" , "Biological" , "(Compound) containing carbon" .)