inefficient
Americanadjective
-
not efficient; unable to effect or achieve the desired result with reasonable economy of means.
-
lacking in ability, incompetent.
adjective
-
unable to perform a task or function to the best advantage; wasteful or incompetent
-
unable to produce the desired result
Related Words
See incapable.
Other Word Forms
- inefficiency noun
- inefficiently adverb
Etymology
Origin of inefficient
Explanation
Inefficient things waste time, money, or other resources. Your old inefficient dishwasher uses much more water and electricity than a new model would. Shame on you. Inefficient businesses have trouble making money and growing, and an inefficient city bus system might transport just a few passengers at a time. If your car is inefficient, it gets terrible gas mileage and is expensive to drive. If something is efficient, it's productive and inexpensive. Inefficient has the opposite meaning, which is clear from the "not" prefix in-.
Vocabulary lists containing inefficient
"Sorry, Wrong Number," Vocabulary from the play
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Florida's B.E.S.T. Common Prefixes: in-, im-, il-, ir-
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Lawn Boy
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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.
"Building GP surgeries that sit unoccupied simply to satisfy a Whitehall demand would be an inefficient and ineffective use of the contributions that development can bring to communities," a spokesperson said.
From BBC • Apr. 14, 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
Coal plants, which can’t easily shut down and restart, either operate at a loss during those hours or ramp down to levels that are inefficient and cause mechanical wear and tear, Dorris said.
From The Wall Street Journal • Feb. 28, 2026
However, only one of those ligands actually contributed to enantioselectivity, which made the approach inefficient.
From Science Daily • Feb. 27, 2026
Then he said, “Yeah. Sure. Do you know how inefficient trees are, next to an air factory?”
From "Feed" by M.T. Anderson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
