rational

play

adjective ra·tio·nal \ˈrash-nəl, ˈra-shə-n^əl\

Definition of rational

1a : having reason or understandingb : relating to, based on, or agreeable to reason : reasonable a rational explanation rational behavior
2 : involving only multiplication, division, addition, and subtraction and only a finite number of times
3 : relating to, consisting of, or being one or more rational numbers a rational root of an equation

rationally

adverb

rationalness

noun

See rational defined for English-language learners

See rational defined for kids

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

Origin and Etymology of rational

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

First Known Use: 14th century

rational

noun ra·tio·nal

Definition of rational

: something rational; specifically : rational number

1601

First Known Use of rational

1601

RATIONAL Defined for English Language Learners

rational

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adjective ra·tio·nal \ˈrash-nəl, ˈra-shə-n^əl\

Definition of rational for English Language Learners

: based on facts or reason and not on emotions or feelings
: having the ability to reason or think about things clearly

RATIONAL Defined for Kids

rational

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adjective ra·tio·nal \ˈra-shə-n^əl\

Definition of rational for Students

1 : having the ability to reason Humans are rational creatures.
2 : based on or showing reason rational thinking a rational decision

rationally

adverb

Medical Dictionary

rational

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adjective ra·tio·nal \ˈrash-nəl, -ən-^əl\

Medical Definition of rational

1a: having reason or understandingb: relating to, based on, or agreeable to reason a rational explanation rational behavior
2: using medical treatments based on reason or general principles—used especially of an ancient school of physicians; compare empirical 1a

rationally

\-ē\play adverb

Law Dictionary

rational

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adjective ra·tio·nal \ˈra-shə-nəl\

Legal Definition of rational

1 : having reason or understanding
2 : relating to, based on, or guided by reason, principle, fairness, logic, a legitimate state interest, or a consideration of fact age distinctions are not subject to strict scrutiny, but they must have a rational relationship to a legitimate state interest — In re J. M., 642 A.2d 1062 (1994)