"redbreast, European robin," Middle English ruddoke, from late Old English rudduc, from rudu "red color," related to read "red" (from PIE root *reudh- "red, ruddy") + diminutive suffix -ock.
Entries linking to ruddock
It forms all or part of: bilirubin; corroborate; Eritrea; erysipelas; erythema; erythro-; Radnor; red; redskin; roan; robust; rooibos; Rotwelsch; rouge; roux; rowan; rubella; rubicund; rubric; ruby; ruddock; ruddy; rufous; Rufus; russet; rust.
It is the hypothetical source of/evidence for its existence is provided by: Latin ruber, also dialectal rufus "light red," mostly of hair; Greek erythros; Sanskrit rudhira-; Avestan raoidita-; Old Church Slavonic rudru, Polish rumiany, Russian rumjanyj "flushed, red," of complexions, etc.; Lithuanian raudas; Old Irish ruad, Welsh rhudd, Breton ruz "red."
common small European songbird, 1540s, a shortening of Robin Redbreast (mid-15c.), from masc. personal name Robin, also (in reference to the bird) in the diminutive form robinet. Redbreast alone for the bird is from early 15c., and the Robin might have been added for the alliteration. It ousted the native ruddock. In North America, the name was applied to the red-breasted thrush by 1703.
Robin's egg as a shade of somewhat greenish blue is attested from 1881; it refers to the North American species; the English robin's eggs are pinkish-white and freckled with purplish-red.