(noun, adjective)


1. based on or using reason

- a process of rational inference

- rational thought

Similar word(s): logical, coherent, logical, lucid, demythologised, demythologized, intelligent, reasoning, thinking, reasonable, sane, reasonable, sensible, sane

2. of or associated with or requiring the use of the mind

- the triumph of the rational over the animal side of man

Similar word(s): mental, intellectual, noetic

3. (mathematics) Of a number, capable of being expressed as the ratio of two integers.

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

4. being guided by the intellect (as distinguished from experience or emotion)

- a rational analysis

Similar word(s): intellectual

5. (of a person ) capable of thinking clearly; exhibiting reasonableness

- rational behavior

- rational conduct

Sentences with rational as an adjective:

- Man is a rational creature.

- His statements were quite rational.


1. an integer or a fraction

Definition categories: quantity, real

Sentences with rational as a noun:

- The quotient of two rationals is again a rational.