Etymograph

English

rectum

Rectum comes from Latin rectus ‘straight’, and perhaps goes back to Proto-Indo-European *h₃reǵ-.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₃reǵ-1‘to straighten, direct’uncertain
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₃reǵtós1‘having moved in a straight line’uncertain
  3. Proto-Italicc. 1500–700 BCE*rektos1reconstructed
  4. Latinc. 75 BCE–200 CEregō1‘to keep or lead straight, to guide’
  5. Latinc. 75 BCE–200 CErectus2‘straight’
  6. Latinc. 75 BCE–200 CErectum intestinum2literally ‘the straight intestine’neuter of rectus
  7. New Latinc. 1500–1900rectum2clipping of rectum intestinum
  8. Englishearliest quotation 2012rectum2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin rectus
  2. 2 Wiktionary, English rectum
  3. Earliest quotation in Wiktionary’s entry: 2012, Jacque Wilson, Experts: Alcohol enemas ‘extremely dangerous’: “Using an alcohol enema involves placing a small tube…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₃reǵ-Wiktionary, Latin rectus‘to straighten, direct’uncertain
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₃reǵtósWiktionary, Latin rectus‘having moved in a straight line’uncertain
  3. Proto-Italicc. 1500–700 BCE*rektosWiktionary, Latin rectusreconstructed
  4. Latinc. 75 BCE–200 CEregōWiktionary, Latin rectus‘to keep or lead straight, to guide’
  5. Latinc. 75 BCE–200 CErectusWiktionary, English rectum‘straight’
  6. Latinc. 75 BCE–200 CErectum intestinumWiktionary, English rectumliterally ‘the straight intestine’neuter of rectus
  7. New Latinc. 1500–1900rectumWiktionary, English rectumclipping of rectum intestinum
  8. Englishearliest quotation 2012rectumWiktionary, English rectum. Earliest quotation in Wiktionary’s entry: 2012, Jacque Wilson, Experts: Alcohol enemas ‘extremely dangerous’: “Using an alcohol enema involves placing a small tube…”

The story

Borrowed from New Latin rectum, clipping of Latin rectum intestinum (literally “the straight intestine”), rectum, neuter of rectus (‘straight’).

Full etymology on Wiktionary

Linked words

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

real, rich, royal, regular, regional, rank, arrangement, roy, radar, resource, correct, arrange, rack, ana, rogue, ruler, righteous, upright, regiment, rightly, interrogation, raj, rex, rake, rightful, directory, regal, regimen, regency, rani, anorexia, rajah, rector, rhesus, eldritch, rightness, erectile, riel, aright, dirigible, 74 more

through Proto-Indo-European *h₃reǵtós ‘having moved in a straight line’

right, 6 more

through Latin regō ‘to keep or lead straight, to guide’

source, rule, region, director, dress, direction, direct, regime, realm, regulate, resurrection, regent, erect, insurrection, incorrigible, droit, irregularity, dirge, regula, corregidor, regio, derecho, 45 more

through Latin rectus ‘straight’

address, dresser, undress, dressage, rectify, rectification, rectitude, recto, 5 more

Today it means

noun The terminal part of the large intestine through which feces pass after exiting the colon, but before leaving the body through the anus or cloaca.

Sources

Sources: Wiktionary, “rectum”; the older steps come from the Wiktionary entry for Latin rectus. 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- / rectum

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