failing
     adj 1: unable to meet financial obligations; "a failing business
            venture" [syn: {failed}]
     2: below acceptable in performance; "received failing grades"
     n 1: a flaw or weak point; "he was quick to point out his wife's
          failings" [syn: {weakness}]
     2: failure to reach a minimum required performance; "his
        failing the course led to his disqualification" [ant: {passing}]
Source: WordNet® 2.0