1
general::
1. Depress, sadden, dispirit, as in He's been really bummed out since his girlfriend moved to California. [Slang; late 1960s] 2. Annoy, irritate, vex, as in That haircut will really bum out his parents. [Slang; c. 1970] 3. Fail badly, as in I got through the midterm, but I bummed out totally on the final exam. This usage is student slang. [Late 1960s]
American Heritage Idioms
2
general::
Phrase(s): bum someone out
Sl. to disappoint someone. • This menial job really bums me out. • The bad movie bummed out the entire audience., Phrase(s): bum out
Sl. to have a bad experience. (Originally referred to a bad experience with drugs.) • Are you going to bum out again tonight? • Man, is he bummed out!
McGrawhill's American Idioms And Phrasal Verbs