Literal Translation
To take back some hair from the beast
Actual Meaning
To perk up
Etymology
‘Reprendre du poil de la bête’ would have had a limited meaning, since originally it meant ‘to seek a remedy in what caused the harm’ or
‘to fight fire with fire.’ It would therefore come from the widespread belief that the hair of the animal that had just bitten someone could heal the wound. Actually similar originally to “hair of the dog that bit you” before the meaning expanded!