nihilism

noun7

1. •
   The view that all endeavours are devoid of objective meaning.

   • [T]he band members sweat hard enough to earn their pretensions, and maybe even their nihilism. — 1983
2. •
   A doctrine grounded on the negation of one or more meaningful aspects of life; in particular, the view that nothing in the world actually exists.
3. •
   The rejection of, or opposition to, religious beliefs, (inherent or objective) moral principles, legal rules, etc., often due to the view that life is meaningless.

   • [T]he dire portent of Nihilism, which some persons regard as little more than an extreme protest against absolutism in Government, [...] is an execrable conspiracy against all religion and morality. — 1882
4. •
   Something that is regarded as meaningless.
5. •
   The rejection of non-proven or non-rationalized assertions in the social and political spheres of society.
6. •
   (historical) Alternative letter-case form of Nihilism (“a Russian movement of the 1860s that rejected all authority and promoted the use of violence for political change”).
7. •
   A delusion that oneself or the world, or parts thereof, have ceased to exist.

   • Individuals with schizophrenia often cycle between nihilistic and solipsistic moods—when in the grip of nihilism they appear to have lost experiential contact with their very existence, [...] — 2009