grue

From Middle English gruen, probably from Middle Low German gruwen or Middle Dutch gruwen (compare Dutch gruwen), both from Proto-Germanic *grūwijaną, perhaps ultimately an imitative derivative of Proto-Indo-European *ǵʰers- (“to bristle”), or instead from *gʰer- (“to rub, stroke, grind”).

Back-formation from gruesome.

Probably from gruesome; first used in Jack Vance's Dying Earth universe in the 1940s, but popularized by the text-based computer game Zork in 1980.

Blend of green + blue. The philosophy sense was coined by American philosopher Nelson Goodman in 1955 to illustrate concepts in the philosophy of science. The linguistic sense was coined by American linguist Paul Kay in 1975 as a translation from languages such as Welsh that have a basic cover term that covers both the hues called "green" and "blue" in English.