Main entry: uneffective, ineffective, ineffectual
Definition: not producing an intended effect
Usage: an ineffective teacher; ineffective legislation
Antonyms: effective, effectual, efficacious
Definition: producing or capable of producing an intended result or having a striking effect
Antonyms: toothed
Definition: having teeth especially of a certain number or type; often used in combination
Antonyms: productive
Definition: producing or capable of producing (especially abundantly)
Main entry: ineffective, ineffectual, unable
Definition: lacking in power or forcefulness
Usage: an ineffectual ruler; like an unable phoenix in hot ashes
Antonyms: stiff, strong, potent
Definition: having a strong physiological or chemical effect
Definition: (of a male) capable of copulation
Main entry: futile, unavailing, otiose, ineffectual
Definition: producing no result or effect
Usage: a futile effort; the therapy was ineffectual; an otiose undertaking; an unavailing attempt