Bummer: Slang for Disappointment or Unfortunate Situation

Bummer (noun/adj., informal) = a disappointing, frustrating, or unpleasant experience.

Usage

• Noun: "The concert cancellation was a real bummer."
• Adjective: "What a bummer day." / "That's so bummer." (less common)

Synonyms

• Letdown, downer, drag, disappointment, misfortune, bad break

Register

Casual, conversational. Not vulgar. Appropriate among friends, informal writing. Avoid formal/professional contexts.