euclidean
eu.clid.e.an also eu.clid.i.an \yu.-'klid-e--*n\ aj often cap : of or relating to the geometry of Euclid or a geometry based on similar axioms
Webster's English Dictionaryeu.clid.e.an also eu.clid.i.an \yu.-'klid-e--*n\ aj often cap : of or relating to the geometry of Euclid or a geometry based on similar axioms