- The definition of a real number is any positive or negative number on the number line.
An example of a real number is 1/2, 0, 1, 2, 3, 4, 5, etc.

Three is a real number.

## real number

Math. any rational or irrational number not having an imaginary part

## real number

noun

A number that is either rational or the limit of a sequence of rational numbers.

## real number

Noun

(*plural* real numbers)

- (mathematics) The limit of a convergent sequence of rational numbers, whether the limit is a rational number such as 2, -5, or 2/7 or whether the limit is an irrational number such as the square root of two or the length of the circle whose radius is one.
*Every integer is a real number, but not vice versa.**A***real number**can be regarded abstractly as an equivalence class of Cauchy sequences of real numbers.^{WP}

- (computing) A floating-point number.
*Even if you pass sqrt an integer, it returns a***real number**.

Antonyms