英语词源字典 - 在线词源网站

collaborate (v.)[collaborate 词源字典]: 1871, back-formation from collaborator. Given a bad sense in World War II. Related: Collaborated; collaborating.[collaborate etymology, collaborate origin, 英语词源]
quisle: "To act as a quisling; to betray one's country, especially by collaborating with an occupying enemy", 1940s; earliest use found in The Times. From quisl-, showing (humorous) identification of the ending of quisling as -ing.