A real number that cannot be expressed as a rational number.

synonym: irrational number.

Dutch: irrationaal getal
Polish: niepoliczalność, niemierzalność, niewymierność

Not consistent with or using reason.

Roget 477: intuitive, instinctive, impulsive; independent of reason, anterior to reason; gratuitous, hazarded; unconnected.    unreasonable, illogical, false, unsound, invalid; unwarranted, not following; inconsequent, inconsequential; inconsistent; absonous^†, absonant^†; unscientific; untenable, inconclusive, incorrect; fallacious, fallible; groundless, unproved; non sequitur [Lat.], it does not follow.    deceptive, sophistical, jesuitical; illusive, illusory; specious, hollow, plausible, ad captandum [Lat.], evasive; irrelevant etc. 10.    weak, feeble, poor, flimsy, loose, vague.    irrational; nonsensical etc. (absurd) 497.    foolish etc. (imbecile) 499; frivolous, pettifogging, quibbling; finespun^†, overrefined^†.    at the end of one's tether, au bout de son latin.    ... show more

Roget 84: numeral, complementary, divisible, aliquot, reciprocal, prime, relatively prime, fractional, decimal, figurate^†, incommensurable.    proportional, exponential, logarithmic, logometric^†, differential, fluxional^†, integral, totitive^†.    positive, negative; rational, irrational; surd, radical, real; complex, imaginary; finite; infinite; impossible.    ... show more

Roget 499: unintelligent [Applied to persons], unintellectual, unreasoning; mindless, witless, reasoningless^†, brainless; halfbaked; having no head etc. 498; not bright etc. 498; inapprehensible^†.    weak headed, addle headed, puzzle headed, blunder headed, muddle headed, muddy headed, pig headed, beetle headed, buffle headed^†, chuckle headed, mutton headed, maggoty headed, grossheaded^†; beef headed, fat witted, fat-headed.    weak-minded, feeble-minded; dull minded, shallow minded, lack-brained; rattle-brained, rattle headed; half witted, lean witted, short witted, dull witted, blunt-witted, shallow-pated^†, clod-pated^†, addle-pated^†, addle-brained^†; dim-sighted, short-sighted; thick-skulled; weak in the upper story.    shallow, borne, weak, wanting, soft, sappy, spoony; dull, dull as a beetle; stupid, heavy, insulse^†, obtuse, blunt, stolid, doltish; asinine; inapt etc. 699; prosaic etc. 843; hebetudinous^†.    childish, child-like; infantine^†, infantile, babyish, babish^†; puerile, anile; simple etc. (credulous) 486; old-womanish.    fatuous, idiotic, imbecile, driveling; blatant, babbling; vacant; sottish; bewildered etc. 475.    blockish^†, unteachable Boeotian, Boeotic; bovine; ungifted, undiscerning^†, unenlightened, unwise, unphilosophical^†; apish; simious^†.    foolish, silly, senseless, irrational, insensate, nonsensical, inept; maudlin.    narrow-minded etc. 481; bigoted etc. (obstinate) 606; giddy etc. (thoughtless) 458; rash etc. 863; eccentric etc. (crazed) 503.    [Applied to actions] foolish, unwise, injudicious, improper, unreasonable, without reason, ridiculous, absurd, idiotic, silly, stupid, asinine; ill-imagined, ill-advised, ill-judged, ill-devised; mal entendu [Fr.]; inconsistent, irrational, unphilosophical^†; extravagant etc. (nonsensical) 497; sleeveless, idle; pointless, useless etc. 645; inexpedient etc. 647; frivolous etc. (trivial) 643.    ... show more

Roget 452: vacant, unintellectual, unideal^†, unoccupied, unthinking, inconsiderate, thoughtless, mindless, no-brain, vacuous; absent etc. (inattentive) 458; diverted; irrational etc. 499; narrow-minded etc. 481.    unthought of, undreamt 'of, unconsidered; off one's mind; incogitable^†, not to be thought of.    ... show more

Polish: nieracjonalny, irracjonalny

Real but not expressible as the quotient of two integers.

Polish: niewymierny