A sign of love to the French (3)
I believe the answer is:
leo
'a sign' is the definition.
(star sign)
'love to the french' is the wordplay.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'to' says to put letters next to each other (I've seen this in other clues).
'the french' becomes 'le' (**).
'o' after 'le' is 'LEO'.
'of' is the link.
(Other definitions for leo that I've seen before include "A constellation; several popes" , "Pope" , "Singer-songwriter Sayer, b. 1949" , "house" , "one of several popes" .)