rational

Capable of reasoning.

Logically sound; not self-contradictory or otherwise absurd.

Healthy or balanced intellectually; exhibiting reasonableness.

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.