Rational — Meaning, Definition & Synonyms

adjective noun /ˈra-sh(ə-)nəl/ ra·tio·nal

Meaning & Definition of Rational

Rational (adjective)

  1. having reason or understanding
  2. relating to, based on, or agreeable to reason, reasonable
  3. involving only multiplication, division, addition, and subtraction and only a finite number of times

Rational (noun)

  1. something rational; specifically, rational number

Rational (adjective) — Senses, Synonyms & Antonyms

  1. having the ability to reason

    "human beings are rational creatures"

    similar: intelligent, reasonable, reasoning, thinking
    related: analytic, logical, brainy, cerebral, highbrow, highbrowed, intellectual, cognitional, cognitive, mental, levelheaded, practical, sane, sensible, sober
    opposite: irrational, nonrational, nonthinking, unintelligent, unreasonable, unreasoning, unthinking
    near: brainless, dense, doltish, dopey, dorky (slang), dull, dumb, fatuous, half-witted, mindless, obtuse, senseless, slow, stupid, thickheaded, fallacious, groundless, illogical, invalid, nonsensical

  2. according to the rules of logic

    "insisted there was a rational explanation for the strange creaking noises and that there were no such things as ghosts"

    similar: analytic, coherent, consequent, good, logical, reasonable, sensible, sound, valid, well-founded, well-grounded
    related: a posteriori, a priori, syllogistic, cognitive, empirical, defendable, defensible, justifiable, maintainable, supportable, sustainable, tenable
    opposite: illegitimate, illogical, incoherent, inconsequent, inconsequential, invalid, irrational, unreasonable, unsound, weak
    near: casuistic, eristic, fallacious, misleading, sophistic, specious, unarticulated, unscientific, absurd, cockeyed, crazy, daffy, fatuous, half-baked, half-witted, harebrained, insane, loony, mad, nonsensical, nutty, preposterous, simpleminded, stupid, weak-minded, witless, senseless, thoughtless, uncompelling, unconvincing

  3. based on sound reasoning or information

    "betting all of your savings on the lottery is not a rational move"

    similar: commonsense, commonsensible, commonsensical, firm, good, hard, informed, just, justified, levelheaded, logical, reasonable, reasoned, sensible, sober, solid, valid, well-founded
    related: actual, real, true, certain, sure, certified, validated, verified, confirmed, corroborated, substantiated, cogent, convincing, colorable, credible, plausible
    opposite: groundless, illogical, invalid, irrational, nonrational, nonsensical, nonvalid, unfounded, uninformed, unjustified, unreasonable, unreasoned, unsound
    near: unsubstantiated, unsupported, unwarranted, flimsy, implausible, unconvincing, weak, fallacious, false, misguided, misled

Synonyms, Thesaurus & Another Word for Rational

The most common words with a similar meaning to Rational:

intelligent, reasonable, reasoning, thinking, analytic, coherent, consequent, good, logical, sensible, sound, valid, well-founded, well-grounded, commonsense, commonsensible, commonsensical, firm, hard, informed, just, justified, levelheaded, reasoned, sober, solid

Antonyms & Opposite Words for Rational

Words with the opposite meaning of Rational:

irrational, nonrational, nonthinking, unintelligent, unreasonable, unreasoning, unthinking, illegitimate, illogical, incoherent, inconsequent, inconsequential, invalid, unsound, weak, groundless, nonsensical, nonvalid, unfounded, uninformed, unjustified, unreasoned

Related Words for Rational

brainy, cerebral, highbrow, highbrowed, intellectual, cognitional, cognitive, mental, practical, sane, a posteriori, a priori, syllogistic, empirical, defendable, defensible, justifiable, maintainable, supportable, sustainable, tenable, actual, real, true, certain, sure, certified, validated, verified, confirmed

Near Antonyms of Rational

brainless, dense, doltish, dopey, dorky, dull, dumb, fatuous, half-witted, mindless, obtuse, senseless, slow, stupid, thickheaded, fallacious, casuistic, eristic, misleading, sophistic, specious, unarticulated, unscientific, absurd, cockeyed, crazy, daffy, half-baked, harebrained, insane

Word Forms of Rational

Derived words: rationally (adverb), rationalness (noun)

Origin & Etymology of Rational

Middle English racional, from Anglo-French racionel, from Latin rationalis, from ration-, ratio

First known use: 14th century

Vocabulary Lists & Topics for Rational

Words & Phrases Containing Rational

rational function, rational number, anti-rational, hyperrational, subrational

Frequently Asked Questions about Rational

What does "Rational" mean?

"Rational" means having reason or understanding. As an an adjective and a noun, it is defined as: having reason or understanding. It has 3 distinct senses.

What is another word for "Rational"?

Other words for "Rational" include intelligent, reasonable, reasoning, thinking, analytic, coherent, consequent and good. The best synonym depends on which meaning of "Rational" you intend.

What are different ways to say "Rational"?

There are 63 words and phrases with a similar meaning to "Rational". Common alternatives include intelligent, reasonable, reasoning, thinking, analytic, coherent, consequent, good, logical and sensible.

What is the opposite of "Rational"?

Antonyms of "Rational" include irrational, nonrational, nonthinking, unintelligent, unreasonable, unreasoning, unthinking and illegitimate. Near antonyms include brainless, dense, doltish and dopey.

How do you use "Rational" in a sentence?

Examples of "Rational" in a sentence: "human beings are rational creatures"; "insisted there was a rational explanation for the strange creaking noises and that there were no such things as ghosts"; "betting all of your savings on the lottery is not a rational move".

Is "Rational" a noun, verb, or adjective?

"Rational" can be used as an adjective and a noun, depending on the context.

Is "Rational" useful for IELTS, TOEFL, and other English exams?

As a C1-level word, "Rational" is typical of Cambridge C1 Advanced (CAE), IELTS band 7.0–8.0, TOEFL iBT 95–113, PTE Academic 76–84, TOEIC Listening & Reading 945+. It is on the Academic Word List, so it appears often in IELTS Academic, TOEFL iBT, PTE Academic, and university texts. Advanced words like this are also useful for the GRE, SAT, GMAT, and LSAT.

How do you pronounce "Rational"?

"Rational" is pronounced /ˈra-sh(ə-)nəl/ and divided into syllables as ra·tio·nal.