faulty 
/ˈfɑ:lti/ adjective
fault·i·er; fault·i·est /ˈfɑ:lti/ adjective [also more faulty; most faulty] : having a mistake, fault, or weakness : imperfect
▪ a faulty argument ▪ a faulty design ▪ The report is based on faulty [=inaccurate] statistics.
▪ a faulty argument ▪ a faulty design ▪ The report is based on faulty [=inaccurate] statistics.
— fault·i·ly /ˈfɑ:ltəli/ adverb
▪ faultily designed parts
/ˈfɑ:ltəli/ adverb ▪ faultily designed parts
— fault·i·ness /ˈfɑ:ltinəs/ noun [noncount]
▪ the faultiness of the design
/ˈfɑ:ltinəs/ noun [noncount] ▪ the faultiness of the design
