1. (mathematics) geometry based on axioms different from Euclid's;

- Example: "non-Euclidean geometries discard or replace one or more of the Euclidean axioms"

WordNet (r) 3.0 (2006):

non-Euclidean geometry n 1: (mathematics) geometry based on axioms different from Euclid's; "non-Euclidean geometries discard or replace one or more of the Euclidean axioms"