rational

[ rash-uh-nl, rash-nl ]

/ ˈræʃ ə nl, ˈræʃ nl /

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adjective

agreeable to reason; reasonable; sensible: a rational plan for economic development.

having or exercising reason, sound judgment, or good sense: a calm and rational negotiator.

being in or characterized by full possession of one's reason; sane; lucid: The patient appeared perfectly rational.

endowed with the faculty of reason: rational beings.

of, relating to, or constituting reasoning powers: the rational faculty.

proceeding or derived from reason or based on reasoning: a rational explanation.

Mathematics.

capable of being expressed exactly by a ratio of two integers.
(of a function) capable of being expressed exactly by a ratio of two polynomials.

Classical Prosody. capable of measurement in terms of the metrical unit or mora.

noun

Mathematics. rational number.

Nearby words

ratio test, ratiocinate, ratiocination, ratiometer, ration, rational, rational form, rational function, rational horizon, rational number, rational operation

Origin of rational

1350–1400; Middle English racional < Latin ratiōnālis, equivalent to ratiōn- (stem of ratiō) reason + -ālis -al¹

SYNONYMS FOR rational

2 intelligent, wise, judicious, sagacious, enlightened.

6 See reasonable.

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ANTONYMS FOR rational

2 stupid.

3 insane.

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Related forms

ra·tion·al·ly, adverbra·tion·al·ness, nounan·ti·ra·tion·al, adjectivean·ti·ra·tion·al·ly, adverb

hy·per·ra·tion·al, adjectivehy·per·ra·tion·al·ly, adverbnon·ra·tion·al, adjectivenon·ra·tion·al·ly, adverbo·ver·ra·tion·al, adjectiveo·ver·ra·tion·al·ly, adverbpre·ra·tion·al, adjectivequa·si-ra·tion·al, adjectivequa·si-ra·tion·al·ly, adverbtrans·ra·tion·al, adjectivetrans·ra·tion·al·ly, adverbul·tra·ra·tion·al, adjectiveul·tra·ra·tion·al·ly, adverbun·ra·tion·al, adjectiveun·ra·tion·al·ly, adverb

Can be confusedrational reasonable (see synonym study at reasonable)

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for rationally

When I fielded telephone calls, my attempts to rationally discuss the subject were complete failures.
Rebels Rise Again Over Flag Banning|Robert Khayat|July 28, 2014|DAILY BEAST
That is a message that might rationally resonate with independents, because it is rooted in fact.
Policy Black Hole: Mitt Romney Keeps His Ideas To Himself|John Avlon|June 22, 2012|DAILY BEAST
The rational mind of course is correct, rationally—but we are not rational animals.
Circumcision’s Deadly Fault Line: Rationality vs. the Metzitzah B’Peh|Kent Sepkowitz|June 10, 2012|DAILY BEAST
In Part 1, we learn that political opinions don't come from rationally developing arguments.
David's Book Club: The Righteous Mind|Noah Kristula-Green|April 9, 2012|DAILY BEAST

Annie Martin is still too peeved to rationally discuss comic Steve Harvey.
Steve Harvey's Bad Romance|Allison Samuels|February 16, 2011|DAILY BEAST
It will not be easy to imagine any third mode materially different, which could rationally be proposed.
The Federalist Papers|Alexander Hamilton, John Jay, and James Madison
Few copies of the New Testament have been sold; yet what else could be rationally expected in these latter times?
Letters of George Borrow|George Borrow
Rationally conceived they are not only consonant with Determinism, but each of them implies it.
Determinism or Free-Will?|Chapman Cohen
We cannot rationally suppose that Adam was a stranger to his duty, either in its nature, manner, or extent.
The Mosaic History of the Creation of the World|Thomas Wood
Since he himself is the way, can we rationally conclude that he would do anything for a guide to us that is unimportant?
Life and Labors of Elder John Kline, the Martyr Missionary|John Kline

British Dictionary definitions for rationally

rational

/ (ˈræʃənəl) /

adjective

using reason or logic in thinking out a problem

in accordance with the principles of logic or reason; reasonable

of sound mind; sanethe patient seemed quite rational

endowed with the capacity to reason; capable of logical thoughtman is a rational being

maths expressible as a ratio of two integers or polynomialsa rational number; a rational function

noun

maths a rational number

Derived Formsrationally, adverbrationalness, noun

Word Origin for rational

C14: from Latin ratiōnālis, from ratiō reason

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for rationally

rational

adj.

late 14c., "pertaining to reason;" mid-15c., "endowed with reason," from Old French racionel and directly from Latin rationalis "of or belonging to reason, reasonable," from ratio (genitive rationis) "reckoning, calculation, reason" (see ratio).

Medicine definitions for rationally

rational

[ răsh′ə-nəl ]

adj.

Having or exercising the ability to reason.

Influenced by reasoning rather than by emotion.

Of sound mind; sane.

Based on scientific knowledge or theory rather than practical observation.

rational

adjective

noun

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Origin of rational

Examples from the Web for rationally

British Dictionary definitions for rationally

rational

adjective

noun

Word Origin for rational

Word Origin and History for rationally

rational

Medicine definitions for rationally

rational

adj.