inefficacious

American  

[in-ef-i-key-shuhs] / ˌɪn ɛf ɪˈkeɪ ʃəs /

adjective

1. not able to produce the desired effect; ineffective.

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inefficacious British  

/ ˌɪnɛfɪˈkæsɪtɪ, ˌɪnɛfɪˈkeɪʃəs, ɪnˈɛfɪkəsɪ /

adjective

1. failing to produce the desired effect

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Other Word Forms

• inefficaciously adverb
• inefficaciousness noun
• inefficacity noun
• inefficacy noun

Etymology

Origin of inefficacious

First recorded in 1650–60; in- ³ + efficacious

Example Sentences

I signed because I wanted to see if a new approach might save me from the miseries of standard treatments that had proven inefficacious.

From New York Times

The report is an important recognition that this preemptive, prefigurative mode of policing and surveillance is not only unconstitutional, but also practically inefficacious if the aim is preventing terror attacks.

From Salon

The report is an important recognition that preemptive, prefigurative mode of policing and surveillance is not only unconstitutional, but also practically inefficacious if the aim is preventing terror attacks.

From Salon

Every argument was brought forward to induce him to stay in La Rochelle, but every argument proved inefficacious.

From Project Gutenberg

It was inefficacious, however, when one of these was involved in sin.

From Project Gutenberg