*Tel qui brille au second rang s’éclipse au premier = A good subordinate often makes a bad leader.
Ranger
Il s’est rangé = He has settled down (after sowing his wild oats).
Rare
Vous devenez bien rare = You are quite a stranger.
Raseur
C’est un raseur (fam.) = He is a bore.
[Une bassinoire = a passive bore.]
Rat
Il est gueux comme un rat d’église = He is as poor as a church mouse.