Rabbi Yom Tov Cheshin in a class (no link) claims the word “Misnaged” or “Misnagdim” was, in fact, coined by Chabad, while the customary term in Breslov writings is “Lomed”, “Lomdim” (so, what does that make them?).
I could add baseless speculations on this point, comparing the insulting term “Misnagdim” applied to those who simply never accepted the reformation of their religion to the Tzedduki designator “Perushim” (separators) for their own opponents (lehavdil), but, wait, I already did…
Ah, never mind.