gloom

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Partial or total darkness; dimness: switched on a table lamp to banish the gloom of a winter afternoon.
2. n. A partially or totally dark place, area, or location.
3. n. An atmosphere of melancholy or depression: Gloom pervaded the office.
4. n. A state of melancholy or depression; despondency.
5. v. To be or become dark, shaded, or obscure.
6. v. To feel, appear, or act despondent, sad, or mournful.
7. v. To make dark, shaded, or obscure.
8. v. Archaic To make despondent; sadden.

Century Dictionary and Cyclopedia

1. n. Dim, glimmering shade; deep twilight; cheerless obscurity; darkness: as, the gloom of a forest.
2. n. Hence — A dark place.
3. n. Cloudiness or heaviness of mind; dejection, melancholy, sullenness, and the like, or an aspect indicative of such feelings.
4. n. A depressing or disheartening condition of affairs; a dismal aspect or prospect.
5. n. In gunpowder-manuf., the drying-oven. Synonyms Obscurity, Dimness, etc. See darkness.— Depression, melancholy, sadness.
6. To appear dimly; be seen in an imperfect or waning light; glimmer; be in darkness or obscurity.
7. To exhibit or produce a somber or melancholy feeling; appear sad, gloomy, or dismal; frown; lower.
8. To darken, or make dark, gloomy, or somber.
9. To fill with gloom or despondency; make gloomy or sad.

Wiktionary

1. n. darkness, dimness or obscurity.
2. n. a melancholy, depressing or despondent atmosphere
3. v. intransitive To be dark or gloomy.
4. v. intransitive to look or feel sad, sullen or despondent.
5. v. transitive To render gloomy or dark; to obscure; to darken.
6. v. transitive To fill with gloom; to make sad, dismal, or sullen.

GNU Webster's 1913

1. n. Partial or total darkness; thick shade; obscurity.
2. n. A shady, gloomy, or dark place or grove.
3. n. Cloudiness or heaviness of mind; melancholy; aspect of sorrow; low spirits; dullness.
4. n. In gunpowder manufacture, the drying oven.
5. v. To shine or appear obscurely or imperfectly; to glimmer.
6. v. To become dark or dim; to be or appear dismal, gloomy, or sad; to come to the evening twilight.
7. v. To render gloomy or dark; to obscure; to darken.
8. v. To fill with gloom; to make sad, dismal, or sullen.

WordNet 3.0

1. n. a state of partial or total darkness
2. n. a feeling of melancholy apprehension
3. n. an atmosphere of depression and melancholy