ineffectual in WordNet English dictionary

1. producing no result or effect
   "a futile effort"; "the therapy was ineffectual"; "an otiose undertaking"; "an unavailing attempt"
   futile  ineffectual  otiose  unavailing 
   
2. not producing an intended effect
   "an ineffective teacher"; "ineffective legislation"
   ineffective  uneffective  ineffectual 
   
3. lacking in power or forcefulness
   "an ineffectual ruler"; "like an unable phoenix in hot ashes"
   ineffective  ineffectual  unable