Synonyms of the word

ineffectual

• adj. unable or insufficient to produce effect; futile.
• adj. worthless.
• adj. weak, indecisive; lacking forcefulness.

futile

• adj. Incapable of producing results; useless; not successful; not worth attempting.

idle

• adj. (obsolete) Empty, vacant.
• adj. Not being use appropriately; not occupied; (of time) with no, no important, or not much activity.
• adj. Not engaged in any occupation or employment; unemployed; inactive; doing nothing.
• adj. Averse to work, labor or employment; lazy; slothful.
• adj. Of no importance; useless; worthless; vain; trifling; thoughtless; silly.
• adj. (obsolete) Light-headed; foolish.
• v. (transitive) To spend in idleness; to waste; to consume.
• v. (intransitive) To lose or spend time doing nothing, or without being employed in business.
• v. (intransitive) Of an engine: to run at a slow speed, or out of gear; to tick over.

impotent

• adj. Lacking physical strength or vigor; weak.
• adj. Lacking in power, as to act effectively; helpless.
• adj. Incapable of sexual intercourse, often because of an inability to achieve or sustain an erection.
• adj. (of a male) Sterile.
• adj. (obsolete) Lacking self-restraint.
• n. A man who has erectile dysfunction.
• n. An impotent or powerless person.

ineffective

• adj. not having the desired effect; ineffectual.
• adj. lacking in ability; incompetent or inadequate.

inefficacious

• adj. Incapable of having the intended consequence.
• adj. Not effective.

inefficient

• adj. Not efficient; not producing the effect intended or desired; inefficacious.
• adj. Incapable of, or indisposed to, effective action; habitually slack or unproductive; effecting little or…
• n. A person who cannot or does not work efficiently.

otiose

• adj. Resulting in no effect.
• adj. Reluctant to work or to exert oneself.
• adj. Having no reason for being (raison d’être); having no point, reason, or purpose.

powerless

• adj. Lacking sufficient power or strength.
• adj. Lacking legal authority.

toothless

• adj. Having no teeth.
• adj. (figuratively) Weak, having no capability of enforcing something.

unable

• adj. Not able; lacking a certain ability.

unavailing

• adj. useless, fruitless, futile.

unproductive

• adj. Not productive; useless; fruitless.

useless

• adj. Without use or possibility to be used.
• adj. Unhelpful, not useful; pointless (of an action).
• adj. (pejorative, of a person) good-for-nothing; not dependable.
• adj. (colloquial, of a person) unable to do well at a particular task or thing. Useless is mildly insulting.