reason

Meanings

1. 1
   noun

   the capacity for rational thought or inference or discrimination

   Some people think that humans are endowed with reason and capable of distinguishing good from evil.

2. 2
   noun

   a fact that logically justifies some premise or conclusion

   There is reason to believe they are lying.

3. 3
   noun

   an explanation of the cause of some phenomenon

   the reason a steady state was never reached was that the back pressure built up too slowly

4. 4
   noun

   a rational motive for a belief or action

   the reason that war was declared

5. 5
   verb

   think logically

   The children must learn to reason

6. 6
   noun

   A cause:

   The reason this tree fell is that it had rotted.

7. 7
   noun

   Rational thinking (or the capacity for it); the cognitive faculties, collectively, of conception, judgment, deduction and intuition.

   Mankind should develop reason above all other virtues.

8. 8
   noun

   Something reasonable, in accordance with thought; justice.

   16th century Edmund Spenser, Lines on his Promised Pension I was promised, on a time, To have reason for my rhyme.

Etymology

From Middle English resoun, reson, from Anglo-Norman raisun (Old French raison), from Latin ratiō, from ratus, past participle of reor (“reckon”), ultimately from Proto-Indo-European *h₂reh₁- (“to think”), reanalysed root of *h₂er- (“to put together”). Displaced native Middle English reden (found in compounds), from Old English rǣden (“condition, stipulation, calculation, direction”), from the same Proto-Indo-European source (compare West Frisian reden (“reason”), Dutch reden (“reason”)). Doublet of ration and ratio.