1580s, probably from gloom (n.) even though that word is not attested as early as this one. Shakespeare used it of woods, Marlowe of persons. Gloomy Gus has been used in a general sense of "sullen person" since 1902, the name of a pessimistic and defeatist newspaper comics character introduced about that time by U.S. illustrator Frederick Burr Opper. Related: Gloomily; gloominess.[gloomy etymology, gloomy origin, 英语词源]