non-Euclidean geometry
noun
1.
geometry based upon one or more postulates that differ from those of Euclid, especially from the postulate that only one line may be drawn through a given point parallel to a given line.
Origin
1870-75;
non-
+
Euclidean
British Dictionary definitions for
non-Euclidean geometry
non-Euclidean geometry
noun
1.
the branch of modern geometry in which certain axioms of Euclidean geometry are restated. It introduces fundamental changes into the concept of space