Etymology
1. O.E.
geolu, geolwe, from P.Gmc.
*gelwaz (cf. O.S., O.H.G.
gelo, M.Du.
ghele, Du.
geel, M.H.G.
gel, Ger.
gelb, O.N.
gulr, Swed.
gul "yellow"), from PIE
*ghel-/*ghol- "yellow, green" (cf. L.
helvus, Gallo-L.
gilvus "light bay;" Gk.
khloros "greenish-yellow color,"
khloe "young green shoot,"
kholos "bile;" O.C.S.
zlutu, Rus.
zeltyj "yellow;" Lith.
zelvas "greenish;" O.C.S.
zelenu, Rus.
zelenyj "green;" Skt.
harih "yellow,"
hiranyam "gold;" Avestan
zari "yellow;" see Chloe). The verb meaning "to become yellow" is O.E.
geoluwian. Adj. meaning "light-skinned" (of blacks) first recorded 1808. Applied to Asiatics since 1787, though the first recorded reference is to Turkish words for inhabitants of India.
Yellow peril translates Ger.
die gelbe gefahr. Sense of "cowardly" is 1856, of unknown origin; the color was traditionally associated rather with treachery.
Yellow-bellied "cowardly" is from 1924, probably a rhyming reduplication of
yellow; earlier
yellow-belly was a sailor's name for a half-caste (1867) and a Texas term for Mexican soldiers (1842, based on the color of their uniforms).
Yellow dog "mongrel" is attested from c.1770; slang sense of "contemptible person" first recorded 1881.
2. From Middle English yelwe, yelou, from Old English ġeolwe, oblique form of Old English ġeolu, from Proto-West Germanic *gelu, from Proto-Germanic *gelwaz, from Proto-Indo-European *ǵʰelh₃wós, from *ǵʰelh₃- (“green, yellow”).
3. Cognate with Scots yella (“yellow”), North Frisian gööl, güül (“yellow”), Saterland Frisian jeel (“yellow”), West Frisian giel (“yellow”), Cimbrian gel, ghéel (“yellow”), Dutch geel (“yellow”), Dutch Low Saxon gael, gel (“yellow”), German gelb, gehl (“yellow”), German Low German gel, geel, gęl, gäl (“yellow”), Luxembourgish giel (“yellow”), Vilamovian gaoł (“yellow”), Yiddish געל (gel), געלב (gelb, “yellow”), Danish, Norwegian Bokmål, Norwegian Nynorsk, and Swedish gul (“yellow”), Faroese and Icelandic gulur (“yellow”). Compare also Welsh gell (“bay, tawny”), Latin helvus (“dull yellow”), Irish geal (“white, bright”), Lithuanian žalias (“green”), Ancient Greek χλωρός (khlōrós, “light green”), Persian زرد (zard, “yellow”), Sanskrit हरि (hari, “greenish-yellow”), Russian жёлтый (žóltyj, “yellow”), Russian зелёный (zeljónyj, “green”). Not related to Italian giallo—see galbinus.
4. The verb is from Middle English yelwen, ȝalowen, ȝolewen, from Old English ġeolwian, from the adjective. See: Irish '
geal'.