Definition: failure to reach a minimum required performance
Usage: his failing the course led to his disqualification; he got two flunks on his report
Definition: a flaw or weak point
Usage: he was quick to point out his wife's failings
Similar words: imperfection, imperfectness
Definition: the state or an instance of being imperfect
Synonyms: failing
Definition: below acceptable in performance
Usage: received failing grades
Similar words: unsatisfactory
Definition: not giving satisfaction
Usage: shops should take back unsatisfactory goods; her performance proved to be unsatisfactory; life is becoming increasingly unsatifactory; our discussion was very unsatisfactory