Etymograph

English

regula

Regula comes from Latin rēgula ‘rule’, from Proto-Indo-European *h₃réǵeti ‘to straighten’, and ultimately from *h₃reǵ-.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₃reǵ-1‘to straighten’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₃réǵeti1‘to straighten’reconstructed
  3. Proto-Italicc. 1500–700 BCE*regō1reconstructed
  4. Latinc. 75 BCE–200 CEregō2‘to rule, govern’
  5. Latinc. 75 BCE–200 CErēgula3‘rule’
  6. Englishtodayregula3

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin rego, which cites Rix
  2. 2 Wiktionary, Latin regula
  3. 3 Wiktionary, English regula

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₃reǵ-Wiktionary, Latin rego, which cites Rix‘to straighten’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₃réǵetiWiktionary, Latin rego, which cites Rix‘to straighten’reconstructed
  3. Proto-Italicc. 1500–700 BCE*regōWiktionary, Latin rego, which cites Rixreconstructed
  4. Latinc. 75 BCE–200 CEregōWiktionary, Latin regula‘to rule, govern’
  5. Latinc. 75 BCE–200 CErēgulaWiktionary, English regula‘rule’
  6. EnglishtodayregulaWiktionary, English regula

Linked words

through Proto-Indo-European *h₃reǵ- ‘to straighten’

right, real, rich, royal, correct, rank, arrangement, roy, radar, arrange, rack, rogue, interrogation, raj, rex, rake, dresser, rector, rani, regency, regal, undress, rajah, dressage, rhesus, eldritch, riel, dirigible, derailleur, rectilinear, interregnum, retch, 75 more

through Proto-Indo-European *h₃réǵeti ‘to straighten’

ana, anorexia, 41 more

through Proto-Italic *regō

regional, resource, directory, regiment, regimen, erectile, erectus, erector, 36 more

through Latin regō ‘to rule, govern’

source, director, direction, address, direct, region, dress, regime, realm, resurrection, ruler, erect, insurrection, regent, rectify, rectum, incorrigible, droit, rectification, dirge, rectitude, recto, rectus, derecho, corregidor, regio, 47 more

through Latin rēgula ‘rule’

rule, irregularity, 8 more

Today it means

noun A book of rules for a religious establishment.

Sources

Sources: Wiktionary, “regula”; the older steps come from the Wiktionary entries for Latin rego, Latin regula. 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 *h₃reǵ- / regula

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