Rational

Webster's Dictionary of the English Language

·noun A rational being.

II. Rational ·adj Relating to the reason; not physical; mental.

III. Rational ·adj Having reason, or the faculty of reasoning; endowed with reason or understanding; reasoning.

IV. Rational ·adj Expressing the type, structure, relations, and reactions of a compound; graphic;

— said of formulae. ·see under Formula.

V. Rational ·adj Agreeable to reason; not absurd, preposterous, extravagant, foolish, fanciful, or the like; wise; judicious; as, rational conduct; a rational man.