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.
Last week, Lufthansa announced a first battery of measures, including that it would ground inefficient aircraft and remove CityLine’s 27 operational aircraft from its summer flight schedule permanently.
From The Wall Street Journal • Apr. 21, 2026
CenterPoint wrote that keeping the plant open “will require substantial investment to support an inefficient and increasingly unreliable asset, rather than advancing affordable and reliable service for customers in southwestern Indiana.”
From Barron's • Apr. 20, 2026
LeBron James had 19 points and 13 assists, and Ayton had 19 points and 11 rebounds while helping keep two-time All-Star Alperen Sengun to 19 points on inefficient six-for-19 shooting.
From Los Angeles Times • Apr. 19, 2026
In a speech in February, Fed governor Christopher Waller put it more colorfully: “You don’t want banks every night … digging around the couch cushions looking for money. That is massively inefficient, stupid.”
From MarketWatch • Apr. 18, 2026
We had to select an even more inefficient route in order to avoid other dust storms.
From "A Rover's Story" by Jasmine Warga
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.
