SYNONYMS
inept, unskilful, unskilled, inexpert, amateurish, unprofessional, lacking ability, bungling, blundering, clumsy, unproficient, inadequate, substandard, inferior, ineffective, deficient, inefficient, ineffectual, no good, not good enough, wanting, lacking, leaving much to be desired
incapable, unfitted, unfit, unsuitable, unqualified
informal useless, pathetic, cack-handed, ham-fisted, not up to it, a dead loss, not up to scratch, not up to snuff
British informal unable to do something for toffee, unable to do something to save one's life, not much cop
vulgar slang half-arsed
British vulgar slang not know one's arse from one's elbow, couldn't organize a piss-up in a brewery