- 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.
- 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.
- Mathematics. rational number.
Origin of rational
SynonymsSee more synonyms on Thesaurus.com
Examples from the Web for rational
Reactionary movements are, first and foremost, not rational.Rage Against GamerGate’s Hate Machine: What I Got For Speaking Up
November 17, 2014
And, as noted with victim blaming, this undermines men as thinking, rational, conscious beings.Hey, Creeps, ‘Compliments’ Are Harassment, Too
November 5, 2014
We should know by now that a rational argument never can touch an affair of the heart.No, Stem Cells Don't Cause Autism
September 11, 2014
Of course, this call for hip-hop artists to speak out comes from a completely sincere and rational place.Not Every Black Celebrity Has to Take a Stand on Ferguson
August 19, 2014
First, laws that treat people differently from one another without a rational justification are unconstitutional.Justice Kennedy Opened the Door to Same-Sex Marriage, Will He Walk Through Next?
Geoffrey R. Stone
August 3, 2014
He is one of the few foreigners who expect a rational answer.Malbone
Thomas Wentworth Higginson
Every rational luxury is to be procured in England by such an income.
Times have changed, and now I enter Calais self-reliant and rational.The Uncommercial Traveller
The commander did what he could to bring me to a rational state of mind.My Double Life
And don't trust him at any time; for when he seems most rational, he's wildest in his talk.Life And Adventures Of Martin Chuzzlewit
- 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
- maths a rational number
Word Origin and History for rational
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).
- 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.