-adjective. Feeling really depressed and sad about an issue. gloomy; morose. Affected by unhappiness or grief; sorrowful; mournful. To be in such a saddened state such as when you miss someone or something that you can't stop thinking about that person or something
Dude... my girlfriend couldn't come over today. I REALLY miss her a lot. I feel really bummed out! :(
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.