BUMMER

[bum.mer] n [prob. modif. of G Bummler loafer, fr. bummeln to dangle, loaf] (1855): one that bums

[2]bummer n [

[2]bum +

[2]-er] (1967) 1: an unpleasant experience (as a bad reaction to a hallucinogenic drug)

2: failure, flop