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 president and his supporters have dismissed that approach as inefficient, overly focused on compromise and unresponsive to the needs of people contending with rapid economic change. —Steven Sloan, Chicago Tribune, 24 Jan. 2026

Reaching customers in suburban and rural areas through traditional retail was inefficient and costly. —Paula De La Cruz, Forbes.com, 23 Jan. 2026

This is a desperate, inefficient way to make energy. —Mrigakshi Dixit, Interesting Engineering, 21 Jan. 2026

What’s become inefficient, outdated, or overly burdensome? —Usa Today, USA Today, 19 Jan. 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