Etymograph

English

triangulation

Triangulation comes from Medieval Latin triangulus ‘to triangulate’, from Latin angulus ‘an angle’, and ultimately from Proto-Indo-European *h₂eng- ‘curve, bend’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂eng-1‘curve, bend’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂engulos1reconstructed
  3. Proto-Italicc. 1500–700 BCE*angulos1reconstructed
  4. Latinc. 75 BCE–200 CEangulus1‘an angle’
  5. Medieval Latinc. 600–1500triangulus2as triangulō‘to triangulate’
  6. Medieval Latinc. 600–1500triangulātiō2
  7. Englishearliest quotation 1839triangulation2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin triangulus
  2. 2 Wiktionary, English triangulation
  3. Earliest quotation in Wiktionary’s entry: 1839, T. B. Jervis, London: Printed by Moyes and Barclay: “The season of 1835–36 was employed in carrying on…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂eng-Wiktionary, Latin triangulus‘curve, bend’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂engulosWiktionary, Latin triangulusreconstructed
  3. Proto-Italicc. 1500–700 BCE*angulosWiktionary, Latin triangulusreconstructed
  4. Latinc. 75 BCE–200 CEangulusWiktionary, Latin triangulus‘an angle’
  5. Medieval Latinc. 600–1500triangulusWiktionary, English triangulationas triangulō‘to triangulate’
  6. Medieval Latinc. 600–1500triangulātiōWiktionary, English triangulation
  7. Englishearliest quotation 1839triangulationWiktionary, English triangulation. Earliest quotation in Wiktionary’s entry: 1839, T. B. Jervis, London: Printed by Moyes and Barclay: “The season of 1835–36 was employed in carrying on…”

Equivalent to triangulate + ion

Proto-Indo-European *h₁ey- ‘to go’

Proto-Indo-European *h₁éyti ‘to go, to be going’

Proto-Hellenic *éimi ‘to go’

Ancient Greek εἶμι ‘I go’

Ancient Greek ἰόν ‘going’

English ion

The story

Triangulō is derived from triangulus (‘triangular; triangle’), from trēs (‘three’) + angulus (‘angle; corner’).

Full etymology on Wiktionary

Linked words

through Proto-Indo-European *h₂eng- ‘curve, bend’

ankle, 9 more

through Latin angulus ‘an angle’

angle, angular, 5 more

Today it means

noun A technique in which distances and directions are estimated from an accurately measured baseline and the principles of trigonometry; (countable) an instance of the use of this technique.

Sources

Sources: Wiktionary, “triangulation”; the older steps come from the Wiktionary entry for Latin triangulus. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *h₂eng- / triangulation

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