C1adjective2K

Rational

UK /["/ˈræʃnəl/"]/US /["/ˈræʃnəl/"]/

Definition

based on reason rather than emotions

In simple words: Based on reason and logic.

Examples

  • She gave a rational explanation for her decision.
  • Humans are rational beings capable of complex thought.
  • The committee tried to reach a rational compromise between the two parties.
  • It is not rational to spend more money than you earn.
  • In mathematics, a rational number can be expressed as a fraction.
  • Rational expressions involve ratios of polynomials.
  • A rational choice model assumes decision-makers act logically to maximize benefit.

Usage notes

Use 'rational' when describing thoughts or actions based on logic rather than emotions. It is appropriate in both formal and casual contexts, but may sound too technical in a relaxed conversation.

Grammar pattern

standalone adjective

Memory hint

Think 'rat' in a maze using logic to find the cheese — that's 'rational.'

Collocations

  • be
  • seem
  • highly
  • very
  • completely
  • about
  • be
  • seem
  • highly
  • very
  • completely
  • about

Synonyms

  • reasonable

Antonyms

  • irrational
  • illogical
  • unreasonable

Common mistakes

  • 'Rational' is often confused with 'rationale', which means the reason for something.
  • Some learners might use 'rational' to refer to emotions instead of logic.
  • Incorrectly saying 'more rational' when 'more rational than' is needed for comparison.