noun

1. (usually uncountable) The view that all endeavours are devoid of objective meaning.

2. (usually uncountable) 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 (sense 1).

3. (usually uncountable) The rejection of non-proven or non-rationalized assertions in the social and political spheres of society.

Synonyms: existential nihilism, moral nihilism