Irrationality definitions

Webster's 1828 Dictionary

IRRATIONAL'ITY, n. Want of reason or the powers of understanding.

WordNet (r) 3.0 (2005)

n
1: the state of being irrational; lacking powers of understanding [syn: irrationality, unreason]

Merriam Webster's

noun see irrational I

Webster's 1913 Dictionary

Irrationality Ir*ra`tion*al"i*ty, n. The quality or state of being irrational. ``Brutish irrationaliity.'' --South.

Collin's Cobuild Dictionary

see irrational

Soule's Dictionary of English Synonyms

n. 1. Brutishness, want of reason. 2. Absurdity, folly, foolishness, unreasonableness.

Moby Thesaurus

Urdummheit, aberration, abnormality, alienation, antilogy, brain damage, brainlessness, brainsickness, callowness, childishness, clouded mind, craziness, daftness, dementedness, dementia, derangement, disorientation, distraction, folie, foolishness, furor, ignorance, illogic, illogicality, illogicalness, immaturity, imprudence, inadvisability, inattention, incapacity, inconclusiveness, incongruity, inconsideration, inconsistency, indiscreetness, indiscretion, ineptitude, inexpedience, injudiciousness, insaneness, insanity, invalidity, lackbrainedness, lackwittedness, loss of mind, loss of reason, low IQ, lunacy, madness, mania, mental deficiency, mental derangement, mental disease, mental disorder, mental disturbance, mental illness, mental instability, mental sickness, mental weakness, mind overthrown, mindlessness, mindsickness, oddness, pixilation, pompousness, possession, primal stupidity, puerility, queerness, rabidness, reasonlessness, recklessness, senselessness, shattered mind, sick mind, sickness, slackmindedness, slackwittedness, strangeness, stuffiness, thoughtlessness, unbalance, unbalanced mind, unintellectuality, unintelligence, unreason, unreasonableness, unsaneness, unscientificness, unsensibleness, unsound mind, unsoundness, unsoundness of mind, untenableness, unthoughtfulness, unwisdom, unwiseness, witlessness