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

Prolonged drought, climate change and inefficient irrigation practices have accelerated the depletion of rivers, lakes and aquifers, while overuse in urban centers has intensified land subsidence and infrastructure strain. —Amir Daftari, MSNBC Newsweek, 6 Oct. 2025

If the same flight path were imposed on travel—Kenya to New York to Germany—we’d call it inefficient design. —Chris Maurice, Fortune, 3 Oct. 2025

The consequences of an inefficient waste collection model extend far beyond residents' monthly bills. —Connor Giffin, Louisville Courier Journal, 1 Oct. 2025

This, in turn, can lead to costly and inefficient repairs that not only disrupt traffic flow but also shorten the lifespan of the roadway. —Georgina Jedikovska, Interesting Engineering, 1 Oct. 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