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 reason for this decision may be how the rapid buildout of Colossus incorporated a mix of different Nvidia GPU chips that was very inefficient for AI training workloads, according to reporting by Tom’s Hardware. —Jeremy Hsu, ArsTechnica, 21 May 2026

Modern classical algorithms use other methods but remain inefficient because the execution time increases exponentially with the size of the number to be factored. —Zeeya Merali, Scientific American, 19 May 2026

Chemical leaching can be costly, inefficient, and harmful to the environment. —Georgina Jedikovska, Interesting Engineering, 18 May 2026

For hospice, the real problem is an inefficient payment system. —Howard Gleckman, Forbes.com, 18 May 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