As a Noun: 1. A symbol (|x|) used in mathematics. It consists of upright lines placed on either side of a number (here shown as ‘x’). 2. In mathematics, the value of x regardless of whether it is positive or negative, e.g., +3 and -3 have the same absolute value, which is 3, written as |3|. The absolute value of any number may be thought of as its distance from zero. English = absolute value.