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

This includes putting more tax inefficient investments into tax advantaged accounts, like 401(k), 403(b), 529 college savings accounts, and HSAs, to name just a few. 6. —Jonathan I. Shenkman, Forbes.com, 1 July 2025

Parking has changed greatly over the years in Boise, in part because city planners have tried to get rid of inefficient surface parking lots. —Carolyn Komatsoulis, Idaho Statesman, 1 July 2025

Sunday spotlight The Royals continue to be plagued by inefficient offense. —Jaylon Thompson, Kansas City Star, 29 June 2025

Ondrej Palat is an inefficient contract that the Devils should try shipping out to fund some of those upgrades. —Harman Dayal, New York Times, 21 June 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