inefficient

adjective

in·​ef·​fi·​cient ˌi-nə-ˈfi-shənt 

: not efficient: such as

a

: wasteful of time or energy

inefficient operating procedures

b

: incapable, incompetent

an inefficient worker

c

: not producing the effect intended or desired

inefficient noun

inefficiently adverb

Synonyms

• unsuccessful
• ineffective
• counterproductive

Examples of inefficient in a Sentence

The delivery system was very inefficient.

an inefficient use of fuel

Recent Examples on the Web

There were two other good starts in there as well, but over his last three, he’s been inefficient at best and uncompetitive at worst. —Abbey Mastracco, New York Daily News, 4 Aug. 2025

Extracting plant dyes, whittling a spoon, making felt—these projects are inefficient and, Ginn argues, extremely satisfying. —Sophia Stewart, The Atlantic, 1 Aug. 2025

Airdrops are inefficient, limited in scale, dangerous, incapable of delivering the specialized food and medical care required to save malnourished children. —David Miliband, Time, 29 July 2025

Crowley initially moved smaller amounts of LNG in insulated cargo containers offloaded onto trucks, but this was extremely inefficient. —Christopher Helman, Forbes.com, 28 July 2025

Word History

First Known Use

1750, in the meaning defined above

Rhymes for inefficient

• beneficent
• coefficient
• insufficient
• deficient
• efficient
• omniscient
• proficient
• sufficient

Kids Definition

inefficient

adjective

in·​ef·​fi·​cient ˌin-ə-ˈfish-ənt 

1

: not producing the effect expected or desired

inefficient regulations

2

: wasteful of time or energy

inefficient procedures

especially : accomplishing little relative to the time spent or effort expended

an inefficient worker

inefficiently adverb