WordNet records no synonym and no antonym for hyperbolic geometry. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
(mathematics) a non-Euclidean geometry in which the parallel axiom is replaced by the assumption that through any point in a plane there are two or more lines that do not intersect a given line in the plane
“Karl Gauss pioneered hyperbolic geometry”
Synonyms, antonyms and the broader and narrower relations for hyperbolic geometry come from Princeton University’s WordNet. Full sources and licences.