h₁reudʰ-
“red, ruddy, reddish”Red, reddish, ruddy
One of the few colour terms securely reconstructable to PIE. Regular reflexes include Latin ruber, Greek erythrós, Sanskrit rudhirá, English red, Lithuanian raũdas, and Old Irish ruad.
Discussion
The root *h₁reudʰ- ("red") is one of the few colour terms that can be reconstructed for PIE with a high degree of confidence, a point emphasised by Berlin and Kay's (Basic Color Terms, 1969) cross-linguistic work on colour vocabulary and by Mallory and Adams (1997) in their treatment of PIE material culture. The reconstruction appears in Pokorny (IEW 872–873) and is accepted without reservation in all standard references. The initial laryngeal *h₁ and the final voiced aspirate *-dʰ- are confirmed by the regularity of the reflexes.
Latin ruber ("red") and the related verb rubēre ("to be red") show the expected Italic development with loss of the initial laryngeal and treatment of *-dʰ- as -b-. The derivative vocabulary includes rubrica ("red ochre, rubric," originally a heading written in red ink), rubella, and through French, rouge. The form russus ("reddish") yielded russet and has been connected — controversially — to the ethnonym Rūs, the origin of the name Russia, though the etymology of Rūs remains disputed between the "red-haired" and "rowers" hypotheses. Ernout and Meillet treat the Latin forms under this root.
Greek erythrós (ἐρυθρός, "red") preserves the full-grade vowel with the characteristic Greek prothetic e- and the development of *-dʰ- to -th-. The derivative erythrós gave rise to the modern medical and biological terminology: erythrocyte ("red blood cell"), erythema, and erythropoietin. The ancient toponym Erythrà Thálassa ("Red Sea") is attested from Herodotus onward. Beekes (s.v. ἐρυθρός) confirms the reconstruction and discusses the prothetic vowel.
Sanskrit rudhirá ("red, bloody") retains the full-grade root and the dental aspirate. The adjective functions both as a colour term and as a substantive meaning "blood," a semantic association reflecting the physiological source of redness that is paralleled in other branches (cf. Latin ruber and its proximity to cruor "blood"). Avestan raoidita- ("red") shows the Iranian reflex.
In Germanic, Proto-Germanic *raudaz yields Gothic rauds, Old English rēad (Modern English red), Old High German rōt (Modern German rot), and Old Norse rauðr. Grimm's Law converts *dʰ > *d, which then follows the regular West Germanic voicing patterns. The derivative *rudō ("rust," literally "the red oxidation") gives English rust and German Rost. Lithuanian raũdas ("reddish-brown"), Old Church Slavonic rŭdŭ ("red"), Old Irish ruad ("red"), and Welsh rhudd complete the principal cognate set across Celtic and Balto-Slavic.
The stability of *h₁reudʰ- contrasts with the instability of other colour terms in IE. Terms for "blue," "green," and "yellow" cannot be reconstructed to PIE with comparable confidence, and even "black" and "white" present difficulties. This asymmetry accords with the findings of Berlin and Kay, who established that "red" is cross-linguistically the first chromatic term to be lexicalised after the achromatic "black" and "white." The PIE colour system, insofar as it can be recovered, appears to have included *h₁reudʰ- as its primary chromatic term.
Laryngeal Analysis
Initial h₁ (non-colouring).
Ablaut
Full grade *h₁reudʰ-, zero grade *h₁rudʰ-.