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

used inefficient measures

inefficient noun

inefficiently adverb

Synonyms of inefficient

• 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

In addition, since many pre-flight tasks involve phone and computer touchscreens and the use of bare hands, a crew member who has to constantly put on and take off gloves would probably find the process both annoying and inefficient. —Joey Skladany, Travel + Leisure, 9 Apr. 2026

Go much faster, and the drag can make a sedan as inefficient as an SUV. —Camila Domonoske, NPR, 7 Apr. 2026

The resulting algorithm introduced several key innovations, including starting routes from dense clusters of items and flexibly abandoning inefficient routes to improve overall system performance. —Jeremy Kahn, Fortune, 7 Apr. 2026

Advocates say the system is not only inefficient but inhumane. —Jim Defede, CBS News, 5 Apr. 2026

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