noun, masculine/kɔ.la.bɔ.ʁa.tœʁ/plural: collaborateurs
collaborator; one who collaborates or has collaborated with the Nazis, fascists or another enemy; traitorous collaborator
Synonyms: collabo
From Late Latin collabōrāre + -ateur, or constructed from collaborer + -eur; eventually from Latin col- (“with, together”) + labor (“work”).