Min·kow·ski spacetime 
(m
ĭn-kôf
sk
ē)
n. A four-dimensional spacetime with no curvature, assumed in the theory of special relativity. The curved spacetime of general relativity appears to be a Minkowski spacetime at any given point near an observer, much as the earth appears basically flat in the vicinity of someone standing on a plain.
[After Hermann Minkowski (1864-1909), Russian-born German mathematician who first described such a spacetime mathematically.]