Meaning of rational

ra•tion•al

Pronunciation: (rash'u-nl, rash'nl), [key]
— adj.
  1. agreeable to reason; reasonable; sensible: a rational plan for economic development.
  2. having or exercising reason, sound judgment, or good sense: a calm and rational negotiator.
  3. being in or characterized by full possession of one's reason; sane; lucid: The patient appeared perfectly rational.
  4. endowed with the faculty of reason: rational beings.
  5. of, pertaining to, or constituting reasoning powers: the rational faculty.
  6. proceeding or derived from reason or based on reasoning: a rational explanation.
    1. capable of being expressed exactly by a ratio of two integers.
    2. (of a function) capable of being expressed exactly by a ratio of two polynomials.
  7. capable of measurement in terms of the metrical unit or mora.
—n.
  1. See
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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