gloom

UK: /ˈgluːm/ US: /glum/ ,(glo̅o̅m)

WordReference Random House Learner's Dictionary of American English © 2025

gloom /glum/   n. [uncountable]

1. total or partial darkness;
   dimness:
   couldn't see in the gloom.
2. a state of sadness or depression:
   I was filled with gloom.

WordReference Random House Unabridged Dictionary of American English © 2025

gloom  (glo̅o̅m), n. 

1. total or partial darkness;
   dimness.
2. a state of melancholy or depression;
   low spirits.
3. a despondent or depressed look or expression.

v.i. 

4. to appear or become dark, dim, or somber.
5. to look sad, dismal, or dejected;
   frown.

v.t. 

6. to fill with gloom;
   make gloomy or sad;
   sadden.
7. to make dark or somber.

• 1300–50; Middle English gloumben, glomen to frown, perh. representing Old English *glūmian (akin to early German gläumen to make turbid); see glum

gloom′ful, adj. 
gloom′ful•ly, adv. 
gloom′less, adj. 
Synonyms

• 1. shadow, shade, obscurity.
• 2. dejection, despondency, sadness.

Antonyms

• 1. brightness.
• 2. cheerfulness.

Collins Concise English Dictionary © HarperCollins Publishers::

gloom / ɡluːm/ noun

1. partial or total darkness
2. a state of depression or melancholy
3. an appearance or expression of despondency or melancholy
4. a dim or dark place

verb

1. (intransitive) to look sullen or depressed
2. to make or become dark or gloomy

Etymology: 14th Century gloumben to look sullen; related to Norwegian dialect glome to eye suspiciously