noun, masculine/ʁə.bʁu.sje/plural: rebroussiers
rebel, dissenter, contrarian, naysayer
Analysable as rebrousser + -ier, but said to be from Occitan rebroussiè (“churlish, surly; the opposite to others”), from Latin reburrus (“with bristling hair”). Compare à rebours and à rebrousse-poil, both ultimately from the same Latin word.