rational
adjectivenounnouncommon in dialogue
- //ˈɹæʃ(ə)nəl//
Capable of reasoning.
adjective
- 1
Capable of reasoning.
Man is a rational creature.
The utility of valid arguments is a monument to our frailty: to the fact that we are not completely rational beings.
- 2
Capable of reasoning. Behaving according to some partial order of preferences.
- 3
Logically sound; not self-contradictory or otherwise absurd.
His statements were quite rational.
Prevention for the future is now almost universally allowed to be the only rational plea for the infliction of punishment; but this, when left to the arbitrary discretion of individuals, always has been found, and always will be found, to degenerate into the exercise of revenge for the past.
- 4
Healthy or balanced intellectually; exhibiting reasonableness.
rational conduct
Temperature 99.8 degrees. Pulse 104. She was quite conscious and rational at times, at others very noisy.
The [Isaac] Newton that emerges from the [unpublished] manuscripts is far from the popular image of a rational practitioner of cold and pure reason.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.
- 5
Comprising, or expressible as, a ratio Of a number, capable of being expressed as the ratio of two integers.
¾ is a rational number, but √2 is an irrational number.
- 6
Comprising, or expressible as, a ratio Of an algebraic expression in indeterminates, or more generally a function: capable of being expressed as the ratio of two polynomials.
- 7
Comprising, or expressible as, a ratio Of a variety: (informally) geometrically simple almost everywhere; (formally) birationally equivalent to projective space
- 8
Comprising, or expressible as, a ratio Of a function between varieties: acting as a morphism on an open subset of its domain.
- 9
Comprising, or expressible as, a ratio Of a point on an algebraic variety over a field: whose coordinates belong to the field in question (in contrast to those points of the variety which are only defined over the algebraic closure of the base field).
- 10
obsoletesynonymous replacement for "condensed" in condensed formula.
Etymology
From Old French rationel, rational, from Latin rationalis (“of or belonging to reason, rational, reasonable; having a ratio”), from ratio (“reason; calculation”).
noun
- 1
A rational number: a number that can be expressed as the quotient of two integers.
The quotient of two rationals is again a rational.
noun
- 1
historicalThe breastplate worn by Israelite high priests.
The Rationale of iudgement alſo thou shalt mke with embrodered worke of diuers colours, according to the workmanship of the Ephod of gold, hyacinth, and purple, and ſcarlet twiſe died, and twiſted ſilke.
Etymology
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. Translation of λογεῖον (logeîon) or perhaps λόγιον (lógion, “oracle”) in the Septuagint version of Exodus 28.
Forms
- plural
- rationals
- comparative
- more rational
- superlative
- most rational