- 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 for rational on Thesaurus.com
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
July 28, 2014
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
June 22, 2012
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
June 10, 2012
In Part 1, we learn that political opinions don't come from rationally developing arguments.David's Book Club: The Righteous Mind
April 9, 2012
Annie Martin is still too peeved to rationally discuss comic Steve Harvey.Steve Harvey's Bad Romance
February 16, 2011
His worthy brother, the Major, might have been as rationally suspected.The Group
They acted "instinctively," or automatically, not rationally.Folkways
William Graham Sumner
All I have to ask is that we talk reasonably and rationally about it.The Papers And Writings Of Abraham Lincoln, Volume Three
To a man there is but one choice that he can rationally make, a marriage of love.
Outside of America there are no cars that are so rationally devised.Following the Equator, Complete
Mark Twain (Samuel Clemens)
- 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 rationally
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.