Etymology Probably from Middle Low German glum (“glum”), related to German dialectal glumm (“gloomy, troubled, turbid”). More at gloomy.
1
Despondent; moody; sullen.
I[…]frighten people by my glum face.1857–1859, W[illiam] M[akepeace] Thackeray, The Virginians. A Tale of the Last Century, volume (please specify |volume=I or II), London: Bradbury & Evans, […], published 1858–1859, →OCLC:
[…] and the prospect of three more days of teaching before the weekend break, Mr. MacPherson felt unusually glum.1959, Mordecai Richler, The Apprenticeship of Duddy Kravitz:
2 more examples
A glummer look replaced the already glum look on Arthur Dent's face.1982, Douglas Adams, Life, the Universe and Everything, page 23:
U.S. Solicitor General Elizabeth Prelogar, who had sought to save Chevron during hours of argument in January, looks slightly glum in her seat at the counsel tables.2024 June 28, Mark Walsh, “Consider the wild gray squirrel, Kagan rebukes her colleagues as court overrules Chevron”, in SCOTUSblog:
Etymology From Middle English glomen, glommen, glomben, gloumben (“to frown, look sullen”), from *glom (“gloom”). More at gloom. The noun is from Middle English glome, from the verb.
1
Obsolete To look sullen; to be of a sour countenance; to be glum.
upon me he gan to loure and glum, Enforcing him so for to ryse withall, But that I shortly unto hem did cum, With his thre hedes he spytte all his venum1509, Stephen Hawes, The Passetyme of Pleasure:
glum
noun
Etymology From Middle English glomen, glommen, glomben, gloumben (“to frown, look sullen”), from *glom (“gloom”). More at gloom. The noun is from Middle English glome, from the verb.