verb/ʁə.pʁɑ̃.dʁə dy pwal də la bɛt/
to take a hair of the dog that bit one (to take an alcoholic drink the morning after to try and cure a hangover); to get a second wind, to get better, to regain one's strength, to get back on one's feet, to bounce back
Synonyms: rallumer la chaudière, soigner le mal par le mal, se requinquer
Literally, “to take back the hair of the beast”. From the popular belief that application of the hair of an animal that has bit the applicator will heal the animal bite. Semantic shift from "to do X" to "to experience the result of doing X".