Couple of the French get nothing (3)
I believe the answer is:
Here is my best explanation:
'couple' is the definition.
('duo' can be a synonym of 'couple')
'of the french get nothing' is the subsidiary indication.
'of the french' becomes 'du'.
'get' is a charade indicator (letters next to each other).
'nothing' becomes 'o' (looks like zero - 0).
(Other definitions for duo that I've seen before include "Performing pair", "Pair (of people, things)", "Pair of people/things", "entertainers such as Eric and Ernie", "Pair of performers", "Two-person act", "Brace", "Two people", "Pair of singers" and "Performing couple".)