Gloomy describes a dark, dim atmosphere or a sad, pessimistic mood. On a gloomy day, thick clouds block the sun and everything looks gray and shadowy. A gloomy basement might have poor lighting and feel damp and unwelcoming.

The word also describes feelings and attitudes. Someone in a gloomy mood feels sad or discouraged, seeing the negative side of things. If your friend predicts a gloomy outcome for the school play, they're expecting it to go badly. A gloomy person tends to focus on what might go wrong rather than what might go right.

When describing places, gloomy suggests more than just darkness. It can carry a feeling of sadness or oppression. An abandoned house might look gloomy with its broken windows and overgrown yard. A forest on an overcast day can feel gloomy when shadows fill the spaces between trees.

The opposite of gloomy is cheerful or bright, whether you're talking about weather, rooms, or someone's outlook.