noun
transcendental number
A number that is not algebraic, i.e., not a root of any non-zero polynomial with rational coefficients. Technical term used in mathematics.
円周率πは超越数であることが知られている。
It is known that the circular constant π is a transcendental number.
代数的数 (algebraic number) is the opposite of 超越数: a number that is a root of a non-zero polynomial with rational coefficients.
From 超越 (transcendence) + 数 (number). The term is a direct translation of the English 'transcendental number', coined in the context of modern mathematics.