Meaning

noun a revolutionary doctrine that advocates destruction of the social system for its own sake

noun the delusion that things (or everything, including the self) do not exist; a sense that everything is unreal

noun complete denial of all established authority and institutions

originProbably borrowed from French nihilisme, German Nihilismus, or Late Latin nihilismus; the French, German, and Latin words are derived from Latin nihil (“indefinite nothing”), from nihilum (“nothing”), from ne- (prefix negating the principal meaning) + hīlum (“a trifle; not in the least”). The English word is cognate with Italian nichilismo, Spanish nihilismo, Russian нигили́зм (nigilízm),…

Etymology from Wiktionary, CC BY-SA 3.0