What is the meaning of Rational?

Capable of reasoning.

Logically sound; not self-contradictory or otherwise absurd.

Healthy or balanced intellectually; exhibiting reasonableness.

Comprising, or expressible as, a ratio

1. Of a number, capable of being expressed as the ratio of two integers.

   Of a number, capable of being expressed as the ratio of two integers.

   Of an algebraic expression in indeterminates, or more generally a function: capable of being expressed as the ratio of two polynomials.

   Of a variety: (informally) geometrically simple almost everywhere; (formally) birationally equivalent to projective space

   Of a function between varieties: acting as a morphism on an open subset of its domain.

   Of a point on an algebraic variety over a field: whose coordinates belong to the field in question (in contrast to those points of the variety which are only defined over the algebraic closure of the base field).

   synonymous replacement for "condensed" in condensed formula.

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

   The breastplate worn by Israelite high priests.

   rationale (religious clothing)

   rational

   Source: wiktionary.org