bummer

Short definition from Wiktionary

Noun

1. 1
   A forager, especially in Sherman's March to the Sea of November to December 1864.
2. 2
   An idle, worthless fellow, without any visible means of support; a dissipated sponger.
3. 3
   A lamb (typically the smallest of a multiple birth) which has been abandoned by its mother or orphaned, and as a consequence is raised in part or in whole by humans.
4. 4
   A disappointment, a pity, a shame.
5. 5
   A psychedelic crisis; hallucinogenic drug use producing undesirable dysphoric psychological effects, most often fear, paranoia, and especially horrifying hallucinations; a bad trip.
6. 6
   A gay man.

Interjection

1. 1
   Exclamation of annoyance or frustration at a bummer (disappointment).

Adjective

1. 1
   comparative form of bum: more bum