follow Dictionary.com

Get the details behind our redesign

inefficacious

[in-ef-i-key-shuh s] /ˌɪn ɛf ɪˈkeɪ ʃəs/
adjective
1.
not able to produce the desired effect; ineffective.
Origin
1650-1660
1650-60; in-3 + efficacious
Related forms
inefficaciously, adverb
inefficaciousness, inefficacity
[in-ef-i-kas-i-tee] /ˌɪn ɛf ɪˈkæs ɪ ti/ (Show IPA),
noun
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
British Dictionary definitions for inefficaciousness

inefficacious

/ˌɪnɛfɪˈkeɪʃəs/
adjective
1.
failing to produce the desired effect
Derived Forms
inefficaciously, adverb
inefficacy (ɪnˈɛfɪkəsɪ), inefficaciousness, inefficacity (ˌɪnɛfɪˈkæsɪtɪ) noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source

Word of The Day

Difficulty index for inefficacious

Few English speakers likely know this word

Word Value for inefficaciousness

27
0
Scrabble Words With Friends