amateurish brainless foolish headless ignorant incapable incapable of incompetent ineffective inefficient inept inferior insensate irrational lackbrained lean-minded lean-witted mindless not bright of little brain pea-brained pin-brained reasonless semiskilled senseless slackminded slackwitted unable unable to unaccomplished unbusinesslike uncoached unendowed unfinished unfit unfitted ungifted uninitiated unintellectual unintelligent unpolished unprepared unprimed unprofessional unqualified unreasoning unschooled unskilled untaught unthinking untrained untutored unwise witless