(mathematics) The smallest set containing all limits of convergent sequences of rational numbers.

(complex analysis) Of a complex number a + bi, the value a.

(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 circumference of the circle whose radius is one.

(philosophy) real being

Life outside of a contrived or fantastical environment; often used in comparison to events depicted in drama. / (by extension, sometimes capitalized) Life outside the Internet.

(retronym) an indoor racket sport from which the modern game of tennis (lawn tennis) is descended

Alternative form of real-world

The realm of human experience comprising physical objects, and excluding theoretical constructs, hypotheses, artificial environments, and "virtual" worlds such as the Internet, computer simulations, or the imagination.

Communicated as the events being responded to occur; communicated or proceeding without much delay (compare instantaneous, synchronous)

Alternative form of real McCoy