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

His company argued in a May lawsuit against licenses issued by the regulator NMDPRA that fuel imports undermine the refinery’s investment and make the domestic market inefficient. — Alexander Onukwue, semafor.com, 18 Sep. 2026

Officials previously said the aging tower had become inefficient and obsolete. — Carole Carlson, Chicago Tribune, 18 Sep. 2026

Every individual decision may appear reasonable, yet the total system can still be inefficient. — Magda Paslaru, Forbes.com, 16 Sep. 2026

There are inappropriate procedures and tests, inefficient scheduling, and unused or wasted supplies, to name a few. — Cassandra Thiel, STAT, 8 Sep. 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