spacetime

noun

Etymology: From space + time, as a calque of German Raumzeit, introduced in this sense by Hermann Minkowski. First appears in print c. 1893 in the Philosophical Review.

1. The four-dimensional continuum of the three spatial dimensions plus time.

   “An event is a point in spacetime, specified by the coordinates x, y, z, and t.”

2. An n-dimensional continuum consisting of dimensions of both space and time. Normally spacetime is considered as having 4 dimensions (x, y, z, t), but higher-dimensional spacetimes are often encountered in theoretical physics, e.g. the 5-dimensional spacetime of Kaluza-Klein theory or the 11 dimensions of spacetime in M-theory.

   “a Minkowski spacetime”

   “a 5-dimensional spacetime”

3. A specific region of the universe with mathematically different properties than the surrounding spacetime. Synonymous with "metric" within the context of general relativity.

   “a Schwarzschild spacetime”

   “a Reissner-Nordström spacetime”