1

rational

play
adjective ra·tio·nal \ ˈrash-nəl , ˈra-shə-nᵊl \

Definition of rational

1 a :having reason or understanding
b :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

Examples of rational in a Sentence

  1. human beings are rational creatures

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

Recent Examples of rational from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'rational.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of rational

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


2

rational

noun

Definition of rational

:something rational; specifically :rational number

First Known Use of rational

1601


RATIONAL Defined for English Language Learners

rational

play
adjective

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

play
adjective ra·tio·nal \ ˈra-shə-nᵊl \

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

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

medical Definition of rational

1 a :having reason or understanding
b :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

play \\ adverb

Law Dictionary

rational

play
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)

rationality

play \ˌra-shə-ˈna-lə-tē\ noun

rationally

adverb


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