poil

The French expression à poil refers to body hair - when you are à poil, you're wearing nothing but your own hair. It's equivalent to the English expression "in one's birthday suit," and can be used as an adjective or as a command in numerous expressions: être à poil (to be stark naked) se baigner à poil (to go skinny-dipping) se mettre à poil (to strip down to one's birthday suit) un mec / une fille à poil (a naked guy / girl) À poil ! (Take 'em off!)