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

The old model of network pilot season was terribly inefficient from a business standpoint. —Rick Porter, HollywoodReporter, 21 Feb. 2026

In a game where guards Kaden Gumbs and Mark Drone had inefficient shooting nights, Emmou’s offensive punch proved invaluable. —Caleb Yum, Austin American Statesman, 21 Feb. 2026

Tariffs, however, target specific goods, causing consumers and businesses to shift behavior in inefficient ways to avoid the tax. —Nick Lichtenberg, Fortune, 19 Feb. 2026

In the first halves of the games in this stretch, the offense has been brutally inefficient and sparse. —Jannelle Moore, Mercury News, 16 Feb. 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