Ni"hil*ist, n. [Cf. F. nihiliste. See Nihilism.]
1. One who advocates the doctrine of nihilism; one who believes or teaches that nothing can be known, or asserted to exist.
2. (Politics) A member of a secret association (esp. in Russia), which is devoted to the destruction of the present political, religious, and social institutions.
The noun Nihilist has 2 senses
1. anarchist, nihilist, syndicalist -- an advocate of anarchism
2. nihilist -- someone who rejects all theories of morality or religious belief