1845 (implied in collaborating), "to work with another or others," a back-formation from collaborator or else modeled on French collaborer or directly from Late Latin collaboratus, past participle of collaborare. Given a bad sense in World War II: "Cooperate traitorously with an occupying enemy." Related: Collaborated.
he collaborated with the Nazis when they occupied Paris
colic
coliform
Colin
coliseum
colitis
collaborate
collaboration
collaborator
collage
collagen
collapsable
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