A lot vs. Alot: 9 Grammatical Pitfalls
1580s, probably from gloom even though that word is not attested as early as this one is. Shakespeare used it of woods, Marlowe of persons. Gloomy Gus used in a general sense of "sullen person" since 1940s, from a comic strip character of that name first recorded 1904. Related: Gloomily; gloominess.