ineffective

Adjective

• lacking the ability or skill to perform effectively; inadequate
  • an ineffective administration
    
  • inefficient workers
    

• lacking in power or forcefulness
  • an ineffectual ruler
    
  • like an unable phoenix in hot ashes
    

• not producing an intended effect
  • an ineffective teacher
    
  • ineffective legislation
    

Related words

• Synonyms: 
  inefficient , ineffectual , unable , uneffective
• Antonyms: 
  effective , effectual , efficacious