'irrationality' definitions:

Definition of 'irrationality'

(from WordNet)
noun
The state of being irrational; lacking powers of understanding [syn: irrationality, unreason]

Definition of 'irrationality'

From: GCIDE
  • irrationality \ir*ra`tion*al"i*ty\, n. The quality or state of being irrational; absence of rationality. "Brutish irrationaliity." --South. [1913 Webster]

Synonyms of 'irrationality'

From: Moby Thesaurus