reason

UK: ˈriːz(ə)n | US: ˈriːz(ə)n

Definition
  1. n. 1. A cause, explanation, or justification for an action or event.

  2. n. 2. The power of the mind to think, understand, and form judgments logically.

  3. v. 3. To think, understand, and form judgments logically.

Structure
reas <reckon, calculate>on <noun suffix>
Etymology

reason = reas<reckon, calculate> + on<noun suffix>

  • reas (from Old French raison, Latin rationem "calculation, understanding")
  • on (noun-forming suffix, often indicating an abstract concept)

Etymology Origin:
The word "reason" traces back to Latin ratio, meaning "calculation" or "logical faculty." It entered English via Old French raison, evolving from a concrete sense of "mathematical reckoning" to the abstract idea of "logical thought" or "justification." The suffix -on (from Latin -ionem) solidified its role as a noun representing a mental process. This shift reflects humanity's growing emphasis on structured thought over mere instinct.

Examples
  1. She couldn’t find a valid reason for his absence.

  2. Human reason distinguishes us from other animals.

  3. He tried to reason with the angry crowd.

  4. The judge demanded a clear reason for the appeal.

  5. Use reason, not emotion, to solve this problem.