(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

(mathematics) The branch of mathematics dealing with the real numbers and related structures.

(computing) The duration required by a computer system to complete a particular task.

(mathematics) The horizontal line in the complex plane, every point on which corresponds to a real number

The national anthem of Spain.

(idiomatic) The genuine thing, neither a substitute nor an imitation.

Alternative form of real McCoy

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

(idiomatic, colloquial) To be authentic, true to oneself; to be cool. / (idiomatic, colloquial) In the imperative, an exhortation used as a departing salutation.