rational

[ rash-uh-nl, rash-nl ]
/ ˈræʃ ə nl, ˈræʃ nl /

adjective

noun

Mathematics. rational number.

QUIZZES

TAKE THIS QUIZ TO SEE WHAT YOU KNOW ABOUT HIGH SCHOOL PUNCTUATION!

Commas mark divisions in sentences. Periods end declarative sentences. Apostrophes show possession. Easy, right? Well, punctuation can get pretty tricky—fast. Think you got what it takes to be a punctuation expert? Take our quiz to prove it!
Question 1 of 10
Which of the options below is the best punctuation for the sentence? It__s your turn to pick the movie __ but your sister gets to pick the board game we _ re going to play.

Origin of rational

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

OTHER WORDS FROM rational

WORDS THAT MAY BE CONFUSED WITH rational

rational reasonable (see synonym study at reasonable)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for rational

British Dictionary definitions for rational

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 forms of rational

rationally, 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

Medical definitions for rational

rational
[ răshə-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.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.