rational

Meanings

1. 1
   adj

   having its source in or being guided by the intellect (as distinguished from experience or emotion)

   a rational analysis

2. 2
   adj

   consistent with or based on or using reason

   rational behavior

3. 3
   adj

   capable of being expressed as a quotient of integers

   rational numbers

4. 4
   adj

   Capable of reasoning.

   Man is a rational creature.

5. 5
   adj

   Logically sound; not self-contradictory or otherwise absurd.

   His statements were quite rational.

6. 6
   adj

   Healthy or balanced intellectually; exhibiting reasonableness.

   rational conduct

7. 7
   adj

   Comprising, or expressible as, a ratio

   ¾ is a rational number, but √2 is an irrational number.

8. 8
   noun

   A rational number: a number that can be expressed as the quotient of two integers.

   The quotient of two rationals is again a rational.

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.