irrational
adjective
°Not rational; unfounded or nonsensical.
"an irrational decision"
°(no comparative or superlative) Of a real number, that cannot be written as the ratio of two integers.
"The number π is irrational."
noun
°A real number that can not be expressed as the quotient of two integers, an irrational number.
"the quotient of two irrationals a and b is a rational if and only if there is an integer n>0 and an integer m such that a*n = b*m"