verb/ʁɑ̃.dʁə la pa.ʁɛj/
to return the favor [with à ‘to someone’] (in a favorable sense); to pay back in kind, to pay back in someone's own coin, to get one's own back on [with à ‘someone’] (in an unfavorable sense)
Synonyms: renvoyer l'ascenseur, rendre la monnaie de sa pièce
Compare Italian rendere la pariglia.