redshirt v.

"of a bright, warm color resembling that of blood or of the highest part of the primery rainbow" [Century Dictionary], Middle English rēd, redde, read, reid, from Old English rēad, used of various shades of purple, crimson, scarlet, pink, etc.; also red clothes, dye, ink, wine, or paint, also "having a ruddy or reddish complexion; red-haired, red-bearded;" from Proto-Germanic *rauthan (source also of Old Norse rauðr, Danish rød, Old Saxon rod, Old Frisian rad, Middle Dutch root, Dutch rood, German rot, Gothic rauþs).

This is reconstructed to be from a PIE root *reudh- "red, ruddy," the only color for which a definite common PIE root word has been found. It also is the root of native ruddy, rust, and, via Latin, ruby, rubric, russet, etc.

Along with dead, bread (n.), lead (n.1), its long vowel shortened in or after Middle English. The surname Read, Reid, Reade, etc. represents the old form of the adjective and retains the original Old English long vowel pronunciation. It corresponds to Brown, Black, White; Red itself being rare as a surname. As the color designation of Native Americans in English from 1580s.

In fixed comparisons, red as blood (Old English), roses (mid-13c.), cherry (c. 1400). From Old English as the color characteristic of inflammation, blistering, etc. Of the complexion, lips, etc., "ruddy, rosy, red" (c. 1200); also of person with a healthy complexion or skin color; to be red in the face as a result of powerful emotion or agitation is by c. 1200; to see red "get angry" is an American English expression attested by 1898.

Red as the characteristic color of "British possessions" on a map is attested from 1885. Red-white-and-blue in reference to American patriotism, from the colors of the flag, is from 1840; in a British context, in reference to the Union flag, 1852.

Red rover, the children's game, attested from 1891. Red ball signifying "express" in railroad jargon is by 1904, originally (1899) a system of moving and tracking freight cars. Red dog, type of U.S. football pass rush, is recorded from 1959 (earlier "lowest grade of flour produced in a mill," by 1889). Red meat, that which is ordinarily served or preferred undercooked, is from 1808; the food of wild beasts, hence its figurative use for something that satisfies a basic appetite (by 1792; popular from late 20c.).

Red shift in spectography is first recorded 1923. Red carpet "sumptuous welcome" is from 1934, but the custom for dignitaries is described as far back as Aeschylus ("Agamemnon"); it also was the name of a type of English moth. Red ant is from 1660s.

Middle English shirt, shirte, "garment for the upper body worn next to the skin," from Old English scyrte, from Proto-Germanic *skurtjon "a short garment" (source also of Old Norse skyrta, Swedish skjorta "skirt, kirtle;" Middle Dutch scorte, Dutch schort "apron;" Middle Low German schörte, Middle High German schurz, German Schurz "apron"), which is perhaps related to Old English scort, sceort "short," etc., from PIE root *sker- (1) "to cut," on the notion of "a cut piece."

OED notes that "the meaning of the word in OE. is obscure, as the only instance of its occurrence is a gloss in which the meaning of the Latin word was probably not understood." Lithuanian šarkas "shirt," Old Church Slavonic sraka "tunic," Russian soročka, Finnish sarkki "shirt" perhaps are from Germanic.

Formerly of the chief under-garment worn by both men and women, but in modern use it has long been only that for men; in reference to women's tops, the word was reintroduced 1896.

Bloody shirt, a blood-stained shirt exposed as a symbol of some outrage, to arouse indignation or resentment, is attested from 1580s, usually figurative. Shirt since late 14c. often has been figurative of one's goods or possessions, hence give (someone) the shirt off one's back (1771); lose one's shirt "suffer total financial loss" (1935). To keep one's shirt on "be patient" (1904) is from the notion of (not) stripping down for a fight.