RATIONAL

adj. logical, reasonable; intelligent, prudent; expressible as a whole number (Mathematics)

Rational may be:pertaining to rationalityacting according to the philosophical principles of rationalisma mathematical term for certain numbers; the rational numbersA rational function, a mathematical function which can be written as the ratio of two polynomial functions.the software company Rational Software; now owned by IBM, and formerly Rational Software Corporationthe most central paradigm of  Rational-Emotive TherapyRational, one of the four temperaments according to the Keirsey Temperament Sorter.A common misspelling of "rationale".A company that makes combi's (Rational USA)Rational Wiki
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Adjective
1. consistent with or based on or using reason; "rational behavior"; "a process of rational inference"; "rational thought"
(antonym) irrational
(similar) coherent, logical, lucid
(see-also) logical
2. of or associated with or requiring the use of the mind; "intellectual problems"; "the triumph of the rational over the animal side of man"
(synonym) intellectual, noetic
(similar) mental
3. capable of being expressed as a quotient of integers; "rational numbers"
(antonym) irrational
(pertainym) ratio
(classification) mathematics, math, maths
4. having its source in or being guided by the intellect (distinguished from experience or emotion); "a rational analysis"
(similar) intellectual

adv. rationally, logically, reasonably, intelligently, in the manner of being based on reason

adj. rational, logical, reasonable, intelligent; (Mathematics) expressible as a whole number

(n.)
A rational being.
  

(a.)
Relating to the reason; not physical; mental.
  

(a.)
Having reason, or the faculty of reasoning; endowed with reason or understanding; reasoning.
  

(a.)
Expressing the type, structure, relations, and reactions of a compound; graphic; -- said of formulae. See under Formula.
  

(a.)
Agreeable to reason; not absurd, preposterous, extravagant, foolish, fanciful, or the like; wise; judicious; as, rational conduct; a rational man.