bummer

(informal) A disappointment, a pity, a shame.

(slang, old-fashioned) A psychedelic crisis; hallucinogenic drug use producing undesirable dysphoric psychological effects, most often fear, paranoia, and especially horrifying hallucinations; a bad trip.

(slang, old-fashioned) An idle, worthless fellow, without any visible means of support; a dissipated sponger.

(slang, offensive) A gay man.

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.

(no longer used, historical) A forager, especially in Sherman's March to the Sea of November to December 1864.

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