Act of cooperating traitorously with an enemy that is occupying your country(noun)
WordNet. Princeton University. 2010.
Use "quislingism" in a sentence
"But if one goes by the proportion of prisoners to other casualties, and the amount of quislingism, the totalitarian states come out of the comparison worse than the democracies."
"Nevertheless there is a tinge of quislingism in his attitude, which comes out in the ending of Part I and slightly interferes with the allegory."
"Yet, after this lapse of time, all that is left of him is a comic song and a beautiful tree, which has rested the eyes of generation after generation and must surely have outweighed any bad effects which he produced by his political quislingism."