on-terminating decimal expansion; no exact representable decimal result.

An irrational number has a non-terminating decimal expansion that cannot be written as a finite or repeating decimal. This means that the decimal representation of an irrational number goes on forever without repeating any pattern. Examples of irrational numbers include √2, π, and e. Because their decimal expansions are non-terminating and non-repeating, they cannot be expressed as an exact representable decimal result. Instead, they are usually approximated using a finite number of decimal places.