horosphere

H4O1R1O1S1P3H4E1R1E1

noun

An n-1-dimensional hyperplane in hyperbolic n-dimensional space: it is (in the Poincaré disk) Euclidean-tangent at infinity to the boundary sphere or (in the upper-half-space model) Euclidean-parallel to the boundary hyperplane.

OriginAncient Greek ὅρος →
Scrabble 18
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Meanings

nounhorosphere (plural horospheres)

plural horospheres

  1. An n-1-dimensional hyperplane in hyperbolic n-dimensional space: it is (in the Poincaré disk) Euclidean-tangent at infinity to the boundary sphere or (in the upper-half-space model) Euclidean-parallel to the boundary hyperplane.

Origin

  1. Ancient Greekὅρος“boundary”
  2. Englishhorosphere

A modern scientific coinage, probably from a Latinized spelling of Ancient Greek ὅρος (hóros, “boundary”) (not to be confused with ὧρος (hôros, “year”), which gave rise to many time-related terms) + -sphere

More words from Ancient Greek

Full word history & related roots →
Cite this entry
APA

horosphere. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/horosphere

MLA

“horosphere.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/horosphere. Accessed November 3, 2026.

Chicago

WatkinsX Dictionary, s.v. “horosphere,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/horosphere.

Source: horosphere on Wiktionary, CC BY-SA 4.0.