Origin: Latin suffix -al
Rational has 8 different meanings across 2 categories:
an integer or a fraction
"The solution to the equation was not irrational, as it could be expressed as the rational number three halves."
A rational number: a number that can be expressed as the quotient of two integers.
"The rational on his chest was embroidered with twelve precious stones representing the tribes of Israel."
The breastplate worn by Israelite high priests.
In plain English: A rational person is someone who makes decisions based on logic and reason instead of emotions or impulses.
"The jury listened to his rational before making their final decision on whether he was sane enough to stand trial."
Usage: Use this noun to refer specifically to numbers expressible as fractions, not for general logical reasoning or ancient priestly armor. It is often confused with "irrational," which describes numbers that cannot be written as a simple fraction.
consistent with or based on or using reason
"rational behavior"
"a process of rational inference"
"rational thought"
of or associated with or requiring the use of the mind
"intellectual problems"
"the triumph of the rational over the animal side of man"
having its source in or being guided by the intellect (as distinguished from experience or emotion)
"a rational analysis"
Capable of reasoning.
"The detective proved her rational by quickly deducing the culprit's identity from scattered clues."
The word comes from the Latin rationalis, which meant "of or belonging to reason." This original sense of being reasonable or having a ratio is still reflected in the modern English term.