pseudomartyr means one who dies or suffers like a martyr but (e.g. because of heretical religious views) is not a true martyr. Lexicurio rates it Sui generis — a strength score of 87 out of 100.
Why “pseudomartyr” is a great word
PSEUDOMARTYR — [Noun] One who suffers or dies for a cause considered false or heretical, and whose sacrifice is therefore deemed illegitimate. From the combining form pseudo- (from Greek ψευδής, pseudḗs, "false") + martyr (from Greek μάρτυς, mártys, "witness"). Unlike "martyr" (whose death sanctifies a legitimate faith) or "confessor" (whose survival bears witness), the pseudomartyr’s fate is a testament only to error. It is the heretic burning on a pyre kindled by his own conviction, the zealot perishing for a prophecy that will never dawn, or the soldier falling for a tyrant’s discredited lie—a testament to the unbearable weight of being profoundly, fatally wrong.
Etymology
From pseudo- + martyr.
noun
- One who dies or suffers like a martyr but (e.g. because of heretical religious views) is not a true martyr.