(n.) Lack of capacity or fitness for a task\.

ad lib baseness deficiency disability disablement disqualification extemporaneousness failure falling short faultiness fewness imbecility imperfection improvisation inability inadeptness inadequacy inadequateness inaptitude inaptness inattentiveness incapability incapacitation incapacity incompetency indexterity ineffectiveness ineffectuality inefficiency ineptitude ineptness infancy inferiority insufficiency insufficientness lack of preparation legal incapacity littleness maladjustment maladroitness meanness mediocrity minority none to spare nonfulfillment nonpreparation nonpreparedness nonsatisfaction pedestrianism pettiness planlessness rustiness shabbiness short supply skill-lessness smallness subnormality thoughtlessness too late too little triviality unaptness uncleverness undeftness undexterousness undextrousness unfitness unfittedness unintelligence unpreparedness unproficiency unqualification unqualifiedness unreadiness unschooledness unskillfulness unsuitability unsuitableness unsuitedness untrainedness uselessness vulgarity vulnerability wardship