Definition from Wiktionary, the free dictionary
- rationall (obsolete)
- Capable of reasoning.
- Man is a rational creature.
2001, Mark Sainsbury, chapter 1, Logical Forms — An Introduction to Philosophical Logic, 2nd edition, Blackwell Publishing, ISBN 978-0-63121-679-7, §7, page 32:
- The utility of valid arguments is a monument to our frailty: to the fact that we are not completely rational beings.
- Logically sound; not contradictory or otherwise absurd.
- His statements were quite rational.
- (of a person or personal characteristics) Healthy or balanced intellectually; exhibiting reasonableness.
- rational conduct
2014 June 21, “Magician’s brain”, The Economist, volume 411, number 8892:
- The [Isaac] Newton that emerges from the [unpublished] manuscripts is far from the popular image of a rational practitioner of cold and pure reason. The architect of modern science was himself not very modern. He was obsessed with alchemy.
- (mathematics, arithmetic, number theory, not comparable) Of a number, capable of being expressed as the ratio of two integers.
- ¾ is a rational number, but √2 is an irrational number.
- (mathematics, arithmetic, not comparable) Of an algebraic expression, capable of being expressed as the ratio of two polynomials.
- (chemistry) Expressing the type, structure, relations, and reactions of a compound; graphic; said of formulae.
- (reasonable): absurd, irrational, nonsensical
- (capable of reasoning): arational, irrational, non-rational
- (number theory): irrational
Terms etymologically related to rational
capable of reasoning
reasonable; not absurd
arithmetic: of a number
arithmetic: of an algebraic expression
From Old French rational, from Medieval Latin rationale (“a pontifical stole, a pallium, an ornament worn over the chasuble”), neuter of Latin rationalis (“rational”), for which see the first etymology.
rational (plural rationals)
- (mathematics) A rational number: a number that can be expressed as the quotient of two integers.
- The quotient of two rationals is again a rational.
- A rational being.
- (Can we find and add a quotation of Young to this entry?)
rational number — see rational number
- rational in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
- rational in The Century Dictionary, The Century Co., New York, 1911