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.

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

Word History and Origins

Origin of non-Euclidean geometry¹

First recorded in 1870–75; non- + Euclidean