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