Origin and history of yarrow

"yarrow," a composite herb, mid-13c., from Old French milfoil, from Latin millefolium, literally "thousand leaf," so called from the abundance of its leaves; from mille "thousand" (see million) + folium "leaf" (from PIE root *bhel- (3) "to thrive, bloom").

of the color of gold, butter, egg yolks, etc., a primary color, Middle English yelwe, from Old English geolu, geolwe, "yellow," from Proto-Germanic *gelwaz (source also of Old Saxon, Old High German gelo, Middle Dutch ghele, Dutch geel, Middle High German gel, German gelb, Old Norse gulr, Swedish gul "yellow"), from PIE root *ghel- (2) "to shine," with derivatives denoting "green" and "yellow" (such as Greek khlōros "greenish-yellow," Latin helvus "yellowish, bay").

In Middle English it also was used of a color closer to blue-gray or gray, in reference to frogs or hazel eyes, and as a translation of Latin caeruleus or glauco. Also of light brown animal hair and persons having yellowish skin or complexion, naturally or by age or disease, and in reference to Ethiopians and Saracens.

The meaning "light-skinned" (in reference to Black persons) is recorded by 1808. It was applied to Asians by 1787, in reference to Turkish words for inhabitants of India. Yellow peril, fear that Asiatic peoples will overrun the West or the world, translates German die gelbe gefahr.

The sense of "cowardly" is attested by 1856, of unknown origin; the color earlier was associated rather with jealousy and envy (17c.). Yellow-bellied "cowardly" is from 1924, probably a semi-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; the slang sense of "contemptible person" is recorded by 1881. Yellow fever is attested from 1748, American English (jaundice is a symptom). Yellow alert is by 1968; yellow light as a traffic signal is by 1925. yellow pages by 1908.