ineffectual
in-ef-fec-tu-al
adjective
Not producing the desired effect; lacking competence or power to act.
"His ineffectual efforts failed to resolve the issue."
Thesaurus
Synonyms: impotent, ineffective, unable, otiose, futile, meaningless, useless, unavailing, toothless, uneffective, unproductive
Antonyms: effective, effectual, efficacious