Noun

• S: (n) rational number, rational (an integer or a fraction)
• direct hyponym / full hyponym
• S: (n) fraction (the quotient of two rational numbers)
• S: (n) mantissa, fixed-point part (the positive fractional part of the representation of a logarithm; in the expression log 643 = 2.808 the mantissa is .808)
• S: (n) common fraction, simple fraction (the quotient of two integers)
• S: (n) one-half, half (one of two equal parts of a divisible whole) "half a loaf"; "half an hour"; "a century and one half"
• S: (n) fifty percent (a half expressed as a percentage)
• S: (n) moiety, mediety (one of two (approximately) equal parts)
• S: (n) one-third, third, tierce (one of three equal parts of a divisible whole) "it contains approximately a third of the minimum daily requirement"
• S: (n) two-thirds (two of three equal parts of a divisible whole)
• S: (n) one-fourth, fourth, one-quarter, quarter, fourth part, twenty-five percent, quartern (one of four equal parts) "a quarter of a pound"
• S: (n) three-fourths, three-quarters (three of four equal parts) "three-fourths of a pound"
• S: (n) one-fifth, fifth, fifth part, twenty percent (one part in five equal parts)
• S: (n) one-sixth, sixth (one part in six equal parts)
• S: (n) one-seventh, seventh (one part in seven equal parts)
• S: (n) one-eighth, eighth (one part in eight equal parts)
• S: (n) one-ninth, ninth (one part in nine equal parts)
• S: (n) one-tenth, tenth, tenth part, ten percent (a tenth part; one part in ten equal parts)
• S: (n) one-twelfth, twelfth, twelfth part, duodecimal (one part in twelve equal parts)
• S: (n) one-sixteenth, sixteenth, sixteenth part (one part in sixteen equal parts)
• S: (n) one-thirty-second, thirty-second, thirty-second part (one part in thirty-two equal parts)
• S: (n) one-sixtieth, sixtieth (one part in sixty equal parts)
• S: (n) one-sixty-fourth, sixty-fourth (one part in sixty-four equal parts)
• S: (n) one-hundredth, hundredth, one percent (one part in a hundred equal parts)
• S: (n) one-thousandth, thousandth (one part in a thousand equal parts)
• S: (n) one-ten-thousandth, ten-thousandth (one part in ten thousand equal parts)
• S: (n) one-hundred-thousandth (one part in a hundred thousand equal parts)
• S: (n) one-millionth, millionth (one part in a million equal parts)
• S: (n) one-hundred-millionth (one part in a hundred million equal parts)
• S: (n) one-billionth, billionth (one part in a billion equal parts)
• S: (n) one-trillionth, trillionth (one part in a trillion equal parts)
• S: (n) one-quadrillionth, quadrillionth (one part in a quadrillion equal parts)
• S: (n) one-quintillionth, quintillionth (one part in a quintillion equal parts)
• S: (n) improper fraction (a fraction whose numerator is larger than the denominator)
• S: (n) proper fraction (a fraction with a numerator smaller than the denominator)
• S: (n) decimal fraction, decimal (a proper fraction whose denominator is a power of 10)
• S: (n) circulating decimal, recurring decimal, repeating decimal (a decimal with a sequence of digits that repeats itself indefinitely)
• S: (n) complex fraction, compound fraction (a fraction with fractions in the numerator or denominator)
• S: (n) continued fraction (a fraction whose numerator is an integer and whose denominator is an integer plus a fraction whose numerator is an integer and whose denominator is an integer plus a fraction and so on)
• direct hypernym / inherited hypernym / sister term
• S: (n) real number, real (any rational or irrational number)
• S: (n) complex number, complex quantity, imaginary number, imaginary ((mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1)
• S: (n) number (a concept of quantity involving zero and units) "every number has a unique position in the sequence"
• S: (n) definite quantity (a specific measure of amount)
• S: (n) measure, quantity, amount (how much there is or how many there are of something that you can quantify)
• S: (n) abstraction, abstract entity (a general concept formed by extracting common features from specific examples)
• S: (n) entity (that which is perceived or known or inferred to have its own distinct existence (living or nonliving))

Adjective

• S: (adj) rational (consistent with or based on or using reason) "rational behavior"; "a process of rational inference"; "rational thought"
• S: (adj) intellectual, rational, noetic (of or associated with or requiring the use of the mind) "intellectual problems"; "the triumph of the rational over the animal side of man"
• S: (adj) rational (capable of being expressed as a quotient of integers) "rational numbers"
• domain category
• pertainym
• W: (n) ratio [Related to: rational] (the relative magnitudes of two quantities (usually expressed as a quotient))
• antonym
• derivationally related form
• W: (n) rationalness [Related to: rational] (the quality of being consistent with or based on logic)
• S: (adj) rational (having its source in or being guided by the intellect (as distinguished from experience or emotion)) "a rational analysis"