(archaic) The quality or state of being rational.

plural of rationalizing

(now rare) Rationally, reasonably.

rationing

(philosophy) A specific form of rationality focusing on the most efficient or cost-effective means to achieve a specific end, but not in itself reflecting on the value of that end.

(philosophy) A specific form of rationality focusing on coming to accurate beliefs about the world based on available evidence.

(mathematics) A number that can be expressed as the ratio of two integers.

plural of rational number

(mathematics) The set of numbers that can be expressed as a ratio of integers, often denoted with the bold letter Q, or the blackboard bold letter ℚ.

(mathematics, complex analysis, algebraic geometry) Any function expressible as the quotient of two (coprime) polynomials (and which thus has poles at a finite, discrete set of points which are the roots of the denominator).