bummer

Definitions

Slang

  • noun a bad experience, a disappointment. An American expression (said to have originated in the jargon of the racetrack where it meant a loss which reduced one to the status of a bum) which spread to Britain and Australia in the hippy era of the late 1960s. It is still heard, although by the late 1980s it was dated. The meaning of the term was reinforced by the expression ‘a bum trip’, referring to an unpleasant experience with LSD.
  • noun a male homosexual, in playground usage
http://www.dictionarycentral.com/definition/bummer.html