Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

Thesaurus

inefficacious

adjective

Synonyms and Antonyms of inefficacious

1 not producing the desired result

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

counterproductive, feckless, hamstrung, ineffective, ineffectual, inefficient, inexpedient
Words Related to inefficacious

abortive, bootless, fruitless, futile, nonproductive, pointless, profitless, unavailing, unproductive, unprofitable, unsuccessful, useless, worthless
Near Antonyms of inefficacious

availing, beneficial, helpful, productive, profitable, successful, useful, worthwhile
Antonyms of inefficacious

effective, effectual, efficacious, efficient, expedient, operant, ultraefficient

2 producing no results

  • an inefficacious medication for a rare form of tuberculosis
Synonyms of inefficacious

abortive, barren, bootless, empty, fruitless, futile, ineffective, ineffectual, otiose, profitless, unavailing, unproductive, unprofitable, unsuccessful, useless, vain
Words Related to inefficacious

hollow, idle, meaningless, pointless, valueless, worthless

hopeless, impossible, lost, no-win, unattainable

inadequate, insufficient, lacking, wanting

counterproductive
Phrases Synonymous with inefficacious

in vain, no dice, not worth the candle, of no avail
Near Antonyms of inefficacious

meaningful, worthwhile

adequate, sufficient

applicable, feasible, functional, practicable, practical, realizable, usable (also useable), workable
Antonyms of inefficacious

deadly, effective, effectual, efficacious, efficient, fruitful, potent, productive, profitable, successful, virtuous

Learn More about inefficacious

  1. Dictionary: Definition of inefficacious

Seen and Heard

What made you want to look up inefficacious? Please tell us where you read or heard it (including the quote, if possible).

show comments hide comments

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

milieu

the setting in which something occurs

Get Word of the Day daily email!

TRENDING NOW

  1. Spartan Red Cross Warns of Shelter Conditions

  2. hirsute RIP Burt Reynolds

  3. op-ed NYT Publishes Anonymous Piece

  4. collegiality Kavanaugh Mentions Word in Hearing

  5. mistrial Manafort Guilty on 8 Counts

SEE ALL

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

Ask the Editors

Word Games