Meanings
- uncountablegeometryAbsolute geometry, an axiomatised geometry in which the parallel postulate is absent and not replaced by an alternative, and of which Euclidean geometry and some non-Euclidean geometries are subtypes.
Claim 7. The Euclidean law of cosines holds for any infinitesimal triangle #92;triangleABC in imaginary geometry.
2011, Seth Braver, Lobachevski Illuminated, Mathematical Association of America, page 1881 more example
1879, Frederick Pollock, Introduction, Part 1: Biographical, Leslie Stephen, Frederick Pollock (editors), William Kingdon Clifford, Lectures and Essays, Volume 1, Cambridge University Press, page 14, He liked talking about imaginary geometry, as a matter of pure amusement, to anyone interested in it. But at the same time he attached a serious import to it.
Synonyms: geometry with no parallel postulate
Synonyms & antonyms
nounAbsolute geometry, an axiomatised geometry in which the parallel postulate is absent and not replaced by an alternative, and of which Euclidean geometry and some non-Euclidean geometries are subtypes.
Origin
- Russianмни́мая геометрия
- Englishimaginary geometry
Calque of Russian мни́мая геометрия (mnímaja geometrija), coined by mathematician Nicolai Lobachevsky, probably influenced by мни́мое чи́сло (mnímoje číslo, “imaginary number”), although his precise reasoning is unknown.
More words from Russian
Full word history & related roots →Translations
Russian мни́мая геометрия
- мни́мая геометрия (mnímaja geometrija)geometry with no parallel postulate — see also absolute geometry
Cite this entry
imaginary geometry. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/imaginary%20geometry
“imaginary geometry.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/imaginary%20geometry. Accessed November 3, 2026.
WatkinsX Dictionary, s.v. “imaginary geometry,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/imaginary%20geometry.
Source: imaginary geometry on Wiktionary, CC BY-SA 4.0.