Synonyms

inefficient

American

[in-i-fish-uhnt] / ˌɪn ɪˈfɪʃ ənt /

adjective

not efficient; unable to effect or achieve the desired result with reasonable economy of means.
lacking in ability, incompetent.

inefficient British

/ ˌɪnɪˈfɪʃənt /

adjective

unable to perform a task or function to the best advantage; wasteful or incompetent
unable to produce the desired result

"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

Related Words

See incapable.

Other Word Forms

inefficiency noun
inefficiently adverb

Etymology

Origin of inefficient

First recorded in 1740–50; in- ³ + efficient

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

This complex acts to selectively suppress mRNAs that contain non-optimal codons, effectively reducing the production of inefficient genetic messages.

From Science Daily • Apr. 9, 2026

I disagree — it seems inefficient to pay tax on distributions we ultimately plan to give to charity when QCDs allow the full amount to go tax-free.

From MarketWatch • Apr. 8, 2026

The company says the tools are “designed to reduce the billions of dollars lost annually to inefficient, outdated dispute processes.”

From The Wall Street Journal • Apr. 1, 2026

Notice where things feel awkward, inefficient, or slightly annoying.

From Salon • Mar. 19, 2026

He has a squeaky, inefficient voice that swallows syllables whole.

From "Dreaming in Cuban" by Cristina García

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023