Rational definition

răshə-nəl
Having or exercising the ability to reason.
adjective
20
6
Consistent with or based on reason or good judgment; logical or sensible.

Rational decisions.

adjective
16
3
Able to reason; reasoning; in possession of one's reason or sanity.
adjective
12
4
The definition of rational is something that makes sense or that could be based in fact or someone who behaves and thinks logically.

An example of rational is the provable idea of gravity.

An example of rational is a person who apologizes after an argument when he knows he was at fault.

adjective
4
1
(of a person or personal characteristics) Healthy or balanced intellectually; exhibiting reasonableness.

Rational conduct.

adjective
4
2
Advertisement
Designating or of a real number or quantity expressible as the ratio of two integers, with the second integer not being equal to zero: all integers and fractions are rational numbers.
adjective
3
1
Designating a function expressible as the quotient of two polynomials.
adjective
3
1
Capable of reasoning.

Man is a rational creature.

adjective
3
2
Logically sound; not contradictory or otherwise absurd.

His statements were quite rational.

adjective
3
2
(mathematics, arithmetic, number theory, not comparable) Of a number, capable of being expressed as the ratio of two integers.

Is a rational number, but √2 is an irrational number.

adjective
3
2
Advertisement
(mathematics, arithmetic, not comparable) Of an algebraic expression, capable of being expressed as the ratio of two polynomials.
adjective
2
2
(chemistry) Expressing the type, structure, relations, and reactions of a compound; graphic; said of formulae.
adjective
2
2
(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.

noun
2
2
A rational being.

noun
2
2
A rational number.
noun
8
9
Advertisement
(mathematics) Capable of being expressed as a quotient of integers.
adjective
6
8
Showing reason; not foolish or silly; sensible.

A rational argument.

adjective
2
4
Having or exercising the ability to reason.
adjective
2
4
Consistent with or based on reason or good judgment; logical or sensible.

Rational decisions.

adjective
2
4
Of, based on, or derived from reasoning.

Rational powers.

adjective
3
6
Advertisement
Of sound mind; sane.

Wondered if the eccentric neighbor was not completely rational.

adjective
1
4

Other Word Forms

Noun

Singular:
rational
Plural:
rationals

Origin of rational

  • Middle English racional from Old French racionel from Latin ratiōnālis from ratiō ratiōn- reason reason

    From American Heritage Dictionary of the English Language, 5th Edition

  • 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.

    From Wiktionary

  • From Old French rationel, rational, from Latin rationalis (“of or belonging to reason, rational, reasonable"), from ratio (“reason")

    From Wiktionary