Source : WordNet®

bad luck
     n 1: an unfortunate state resulting from unfavorable outcomes
          [syn: {misfortune}, {tough luck}, {ill luck}] [ant: {good
          fortune}, {good fortune}]
     2: an unpredictable outcome that is unfortunate; "if I didn't
        have bad luck I wouldn't have any luck at all" [syn: {mischance},
         {mishap}]
     3: unnecessary and unforeseen trouble resulting from an
        unfortunate event [syn: {misfortune}]