Etymograph

English

radiate

Radiate comes from Latin radiātus ‘radiated’, from radius ‘spoke of a wheel’, and perhaps ultimately from Proto-Indo-European *neredʰ- ‘extend forth, rise, outward’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*neredʰ-1‘extend forth, rise, outward’uncertain
  2. Latinc. 75 BCE–200 CEradius2‘spoke of a wheel’
  3. Latinc. 75 BCE–200 CEradiō3‘to radiate, furnish with spokes, give out rays, radiate, shine’
  4. Latinc. 75 BCE–200 CEradiātus3‘radiated’perfect passive participle of radiō
  5. Englishearliest quotation 1706radiate3

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin radius
  2. 2 Wiktionary, Latin radio
  3. 3 Wiktionary, English radiate
  4. Earliest quotation in Wiktionary’s entry: 1706, John Locke: “Light radiates from luminous bodies directly to our eyes.”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*neredʰ-Wiktionary, Latin radius‘extend forth, rise, outward’uncertain
  2. Latinc. 75 BCE–200 CEradiusWiktionary, Latin radio‘spoke of a wheel’
  3. Latinc. 75 BCE–200 CEradiōWiktionary, English radiate‘to radiate, furnish with spokes, give out rays, radiate, shine’
  4. Latinc. 75 BCE–200 CEradiātusWiktionary, English radiate‘radiated’perfect passive participle of radiō
  5. Englishearliest quotation 1706radiateWiktionary, English radiate. Earliest quotation in Wiktionary’s entry: 1706, John Locke: “Light radiates from luminous bodies directly to our eyes.”

Linked words

through Latin radius ‘spoke of a wheel’

ray, radius, rayon, 10 more

through Latin radiō ‘to radiate, furnish with spokes, give out…’

laser, 4 more

Another origin of radiate

  1. Latinc. 75 BCE–200 CEradiātus‘radiated’
  2. Englishtodayradiate

Today it means

verb To extend, be sent or spread out from a center like radii.

Sources

Sources: Wiktionary, “radiate”; the older steps come from the Wiktionary entries for Latin radius, Latin radio. 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 *neredʰ- / radiate

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