1.Definition: causing dejection

"A dark gloomy day"

Related Adjective(s):blue, dark, dingy, disconsolate, dismal, drab, drear, dreary, grim, sorry

2.Definition: depressingly dark

"The gloomy forest"

Related Adjective(s):gloomful, glooming, sulky

3.Definition: filled with melancholy and despondency

"Gloomy at the thought of what he had to face", "Gloomy predictions", "A gloomy silence"

Related Adjective(s):blue, depressed, dispirited, down, downcast, downhearted, grim, low