| abortive(inferior, inadequate, limited, feeble, useless) |
| anticlimactic(inferior, inadequate, limited, feeble, useless) |
| barren(inadequate, limited, feeble, useless, vain) |
| bootless(inferior, inadequate, limited, feeble, useless) |
| emasculate(inadequate, limited, feeble, useless, vain) |
| feckless(inferior, inadequate, limited, feeble, useless) |
| feeble(inadequate, limited, useless, vain, unsuccessful) |
| forceless(inferior, inadequate, limited, feeble, useless) |
| fruitless(inferior, inadequate, limited, feeble, useless) |
| futile(inferior, inadequate, limited, feeble, useless) |
| idle(inferior, inadequate, limited, feeble, useless) |
| impotent(inferior, inadequate, limited, feeble, useless) |
| inadequate(limited, feeble, useless, vain, unsuccessful) |
| incompetent(inadequate, limited, feeble, useless, vain) |
| indecisive(inferior, inadequate, limited, feeble, useless) |
| ineffective(adjective, useless, unpolluted, vain, unsuccessful) |
| ineffectual(inadequate, limited, feeble, useless, vain) |
| inefficacious(adjective, inferior, inadequate, limited, feeble) |
| inefficient(inferior, inadequate, limited, feeble, useless) |
| inept(inadequate, limited, feeble, useless, vain) |