A rational number is a number that can be expressed as a ratio of two integers. Some synonyms for this term include "fraction", "quotient", and "ratio". Rational numbers can also be referred to as "proper fractions" when the numerator is smaller than the denominator, or as "improper fractions" when the numerator is larger than the denominator. Another synonym for a rational number is "non-irrational", meaning that the number is not irrational, which is a number that cannot be expressed as a ratio of two integers. Overall, the use of different synonyms for rational numbers can help to clarify the concept and make it easier to understand.