filled with melancholy and despondency
"gloomy at the thought of what he had to face"
"gloomy predictions"
"a gloomy silence"
"took a grim view of the economy"
"the darkening mood"
"lonely and blue in a strange city"
"depressed by the loss of his job"
"a dispirited and resigned expression on her face"
"downcast after his defeat"
"feeling discouraged and downhearted"
Not very illuminated; dim because of darkness, especially when appearing depressing or frightening.
"The gloomy tunnel was barely visible ahead, its dark walls making us feel trapped in the suffocating silence."