Etymograph

English

radius

Radius comes from Latin radius ‘ray’.

  1. Latinc. 75 BCE–200 CEradius1‘ray’
  2. Englishearliest quotation 1674radius1

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, English radius
  2. Earliest quotation in Wiktionary’s entry: 1674, Robert Hooke: “[…] I can do more with a Quadrant, Sextant…”.

Earlier history uncertain. See Wiktionary.

Lineage

  1. Latinc. 75 BCE–200 CEradiusWiktionary, English radius‘ray’
  2. Englishearliest quotation 1674radiusWiktionary, English radius. Earliest quotation in Wiktionary’s entry: 1674, Robert Hooke: “[…] I can do more with a Quadrant, Sextant…”

Linked words

through Latin radius ‘ray’

ray, laser, radiation, radiant, radial, rayon, radiate, 7 more

Today it means

noun The long bone in the forearm, on the side of the thumb.

Sources

Sources: Wiktionary, “radius”. 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 / Latin radius / radius

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