irrational


Also found in: Thesaurus, Medical, Legal, Encyclopedia, Wikipedia.

ir·ra·tion·al

 (ĭ-răsh′ə-nəl)
adj.
1.
a. Not endowed with reason.
b. Affected by loss of usual or normal mental clarity; incoherent, as from shock.
c. Marked by a lack of accord with reason or sound judgment: an irrational dislike.
2.
a. Being a syllable in Greek and Latin prosody whose length does not fit the metric pattern.
b. Being a metric foot containing such a syllable.
3. Mathematics Of or relating to an irrational number.
n. Mathematics
An irrational number.

ir·ra′tion·al·ly adv.
ir·ra′tion·al·ness n.

irrational

(ɪˈræʃənəl)
adj
1. inconsistent with reason or logic; illogical; absurd
2. incapable of reasoning
3. (Mathematics) maths
a. not rational
b. (as noun): an irrational.
4. (Poetry) prosody (in Greek or Latin verse)
a. of or relating to a metrical irregularity, usually the occurrence of a long syllable instead of a short one
b. denoting a metrical foot where such an irregularity occurs
irˈrationally adv
irˈrationalness n

ir•ra•tion•al

(ɪˈræʃ ə nl)

adj.
1. lacking the faculty of reason; deprived of reason.
2. lacking sound judgment or logic: irrational arguments.
3. not controlled or governed by reason: irrational behavior.
4.
a. (of a number) not capable of being expressed exactly as a ratio of two integers.
b. (of a function) not capable of being expressed exactly as a ratio of two polynomials.
c. (of an equation) having an unknown under a radical sign or, alternately, with a fractional exponent.
5. of or pertaining to a syllable in Greek or Latin prosody whose quantity does not fit the meter.
n.
[1425–75; late Middle English < Latin]
ir•ra′tion•al•ly, adv.
ir•ra′tion•al•ness, n.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.irrational - a real number that cannot be expressed as a rational number
real, real number - any rational or irrational number
transcendental number - an irrational number that is not algebraic
algebraic number - root of an algebraic equation with rational coefficients
Adj.1.irrational - not consistent with or using reason; "irrational fears"; "irrational animals"
incoherent - without logical or meaningful connection; "a turgid incoherent presentation"
illogical, unlogical - lacking in correct logical relation
unreasonable - not reasonable; not showing good judgment
rational - consistent with or based on or using reason; "rational behavior"; "a process of rational inference"; "rational thought"
2.irrational - real but not expressible as the quotient of two integers; "irrational numbers"
math, mathematics, maths - a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement
rational - capable of being expressed as a quotient of integers; "rational numbers"

irrational

adjective
2. senseless, wild, crazy, unstable, insane, mindless, demented, aberrant, brainless They behaved in such a bizarre and irrational manner.

irrational

adjective
Not governed by or predicated on reason:
Translations
iracionální
epälooginenirrationaalinen

irrational

[ɪˈræʃənl] ADJ [behaviour, person, belief] → irracional

irrational

[ɪˈræʃənəl] adj
[feeling, behaviour, idea, belief] → irrationnel(le)
an irrational fear of science → une peur irrationnelle de la science
[argument] → irrationnel(le)
to be irrational → être irrationnel

irrational

adj
(= illogical, also Math, Psych) → irrational; fear, beliefunsinnig, irrational; (= not sensible)unvernünftig; he had become quite irrational about iter hatte eine irrationale Einstellung dazu entwickelt; if you maintain X, then it is irrational to deny Ywenn Sie X behaupten, ist es widersinnig or unlogisch, Y zu leugnen
(= not having reason) animalvernunftlos

irrational

[ɪˈræʃənl] adjirrazionale
an irrational fear → una paura irrazionale
he had become quite irrational about it → era diventato piuttosto irragionevole al riguardo

ir·ra·tion·al

n. irracional.
References in classic literature ?
And brave as he might be, it was that sort of bravery chiefly, visible in some intrepid men, which, while generally abiding firm in the conflict with seas, or winds, or whales, or any of the ordinary irrational horrors of the world, yet cannot withstand those more terrific, because more spiritual terrors, which sometimes menace you from the concentrating brow of an enraged and mighty man.
How inconsiderate, how indelicate, how irrational, how unfeeling had been her conduct
No," said he, "I never said any thing so irrational.
My head still ached and bled with the blow and fall I had received: no one had reproved John for wantonly striking me; and because I had turned against him to avert farther irrational violence, I was loaded with general opprobrium.
Catherine caught and perused it eagerly; then she put a few questions to me concerning the inmates, rational and irrational, of her former home; and gazing towards the hills, murmured in soliloquy:
I confess that I felt a more than usual, indeed a quite irrational, perturbation of the blood, as, coming level with her, I dared to look into her face.
hee hath eat'n and lives, And knows, and speaks, and reasons, and discernes, Irrational till then.
These unhappy people were proposing schemes for persuading monarchs to choose favourites upon the score of their wisdom, capacity, and virtue; of teaching ministers to consult the public good; of rewarding merit, great abilities, eminent services; of instructing princes to know their true interest, by placing it on the same foundation with that of their people; of choosing for employments persons qualified to exercise them, with many other wild, impossible chimeras, that never entered before into the heart of man to conceive; and confirmed in me the old observation, "that there is nothing so extravagant and irrational, which some philosophers have not maintained for truth.
Snap that reed again, Watson," cried the apparently irrational young professor.
It is useful to know something of the manners of different nations, that we may be enabled to form a more correct judgment regarding our own, and be prevented from thinking that everything contrary to our customs is ridiculous and irrational, a conclusion usually come to by those whose experience has been limited to their own country.
Yet this singular and almost accidental character of his mission agrees with the divine sign which, according to our notions, is equally accidental and irrational, and is nevertheless accepted by him as the guiding principle of his life.
Regard to the public peace, if not to the rights of the Union, would engage the citizens to whom the contagion had not communicated itself to oppose the insurgents; and if the general government should be found in practice conducive to the prosperity and felicity of the people, it were irrational to believe that they would be disinclined to its support.