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 quality of a child’s public school education being determined by ZIP code is categorically unfair AND inefficient. —Dr. Gisele C. Shorter, Hartford Courant, 19 June 2026

Every inefficient query consumes additional compute resources. —Chhandomay Mandal, Forbes.com, 18 June 2026

But cheaper doesn’t mean inefficient. —Alora Bopray, USA Today, 17 June 2026

The heart of the Cuban economy will still be the state-run enterprises, all of which are incredibly inefficient, don’t work, provide terrible service. —David Frum, The Atlantic, 17 June 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