Capable of reasoning. / Logically sound; not self-contradictory or otherwise absurd. / (of a person or personal characteristics) Healthy or balanced intellectually; exhibiting reasonableness.

(mathematics) A rational number: a number that can be expressed as the quotient of two integers.

(historical) The breastplate worn by Israelite high priests.

A portion of some limited resource allocated to a person or group.

(transitive) To supply with a ration; to limit (someone) to a specific allowance of something. / (transitive) To portion out (especially during a shortage of supply); to limit access to.

Suitable for being rationed.

(archaic) Rational, reasonable.

(now rare) Rationally, reasonably.

The process, or result of rationalizing. / A statement of one's motives, or of the causes of some event. / A reorganization of a company or organization in order to improve its efficiency.

In a rational manner