Meaning

noun a rational motive for a belief or action

noun an explanation of the cause of some phenomenon

noun the capacity for rational thought or inference or discrimination

originFrom 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…

Etymology from Wiktionary, CC BY-SA 3.0