Logically sound; not self-contradictory or otherwise absurd.
His statements were quite rational.
Prevention for the future is now almost universally allowed to be the only rational plea for the infliction of punishment; but this, when left to the arbitrary discretion of individuals, always has been found, and always will be found, to degenerate into the exercise of revenge for the past.
(of a person or personal characteristics) Healthy or balanced intellectually; exhibiting reasonableness.
rational conduct
Temperature 99.8 degrees. Pulse 104. She was quite conscious and rational at times, at others very noisy.
(mathematics, not comparable) Comprising, or expressible as, a ratio
(chemistry, obsolete) synonymous replacement for "condensed" in condensed formula.
noun
(mathematics) A rational number: a number that can be expressed as the quotient of two integers.
The quotient of two rationals is again a rational.
noun
(historical) The breastplate worn by Israelite high priests.