Synonyms of inefficacious

inefficacious

adjective

(ˌ)i-ˌne-fə-ˈkā-shəs 

1

as in unsuccessful

not producing the desired result

his efforts to restore the neglected houseplant back to health were belated and sadly inefficacious

Synonyms & Similar Words

• unsuccessful
• inefficient
• ineffective
• counterproductive
• inexpedient
• ineffectual
• worthless
• useless
• feckless
• futile
• unprofitable
• pointless
• unavailing
• abortive
• nonproductive
• fruitless
• unproductive
• profitless
• hamstrung
• bootless

Antonyms & Near Antonyms

• effective
• efficacious
• efficient
• effectual
• expedient
• operant
• successful
• beneficial
• useful
• helpful
• worthwhile
• profitable
• productive
• ultraefficient
• availing

2

as in futile

producing no results

an inefficacious medication for a rare form of tuberculosis

Synonyms & Similar Words

• unsuccessful
• futile
• useless
• ineffective
• unavailing
• ineffectual
• unprofitable
• in vain
• abortive
• impossible
• insufficient
• fruitless
• vain
• unproductive
• worthless
• inadequate
• profitless
• of no avail
• otiose
• meaningless
• bootless
• barren
• empty
• pointless
• valueless
• not worth the candle
• hollow
• no dice
• hopeless
• lost
• lacking
• idle
• unattainable
• counterproductive
• no-win
• wanting

Antonyms & Near Antonyms

• effective
• successful
• efficient
• profitable
• virtuous
• productive
• fruitful
• deadly
• efficacious
• potent
• sufficient
• worthwhile
• adequate
• meaningful
• effectual
• practical
• feasible
• applicable
• functional
• practicable
• workable
• usable
• realizable
• useable

Examples of inefficacious in a Sentence

Recent Examples on the Web

Most wore inefficacious cloth masks, too. —James Lileks, National Review, 25 Aug. 2022

Day — who grew up watching the spelling bee — came up with the concept of exploring the psyche of a winner with an ultimately inefficacious career in 2015 while at a UCB improv sketch-writing class. —NBC News, 6 Oct. 2020