If you say that something is a bummer, you mean that it is unpleasant or annoying. I had a bummer of a day What a bummer!. a bummer a situation that is disappointing or annoying (BUM)
a bad reaction to a hallucinogenic drug an experience that is irritating or frustrating or disappointing; "having to stand in line so long was a real bummer
{i} lazy person, idle person; bad experience, downer, failure (often of plans); unpleasant aftermath of taking a narcotic drug