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

• counterproductive
• feckless
• hamstrung
• ineffective
• ineffectual
• inefficacious
• inexpedient

Examples of inefficient in a Sentence

The delivery system was very inefficient.

an inefficient use of fuel

Recent Examples on the Web

Windmills, and the rest of this 'JUNK,' are the most expensive and inefficient energy in the world, is destroying the beauty of the environment, and is 10 times more costly than any other energy. —Adeola Adeosun hollie Silverman, MSNBC Newsweek, 21 June 2025

This type of development is inefficient at housing large populations. —Kristian Fors, Oc Register, 19 June 2025

Slower Response Times And Ripe For Cyberattacks During a cyberattack, having a manual process between the infosec team and the storage team is highly inefficient. —Eric Herzog, Forbes.com, 17 June 2025

Wind pollination is highly inefficient and self-pollination does not allow for evolution, so many plant species have evolved to entice and use insects and animals to pollinate themselves. —The San Diego Union Tribune, San Diego Union-Tribune, 14 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