- Contrary to reason or propriety; obviously and flatly opposed to manifest truth; inconsistent with the plain dictates of common sense; logically contradictory; nonsensical; ridiculous; silly. [First attested in the mid 16th century.]
- Dealing with absurdism.
- Having no rational or orderly relationship to people's lives; meaningless; lacking order or value.
- (obsolete) Inharmonious; dissonant. [Attested only in the early 17th century.]
- (philosophy, often preceded by the) The opposition between the human search for meaning in life and the inability to find any; the state or condition in which man exists in an irrational universe and his life has no meaning outside of his existence. [First attested in English in the early 20th century and first used in the mid-19th century in Danish by Kierkegaard.]
- (obsolete) An absurdity. [Attested from the early 17th century until the mid 17th century.]