efficiency

noun

ef·​fi·​cien·​cy i-ˈfi-shən-sē 

plural efficiencies

1

: the quality or degree of being efficient

2

a

: efficient operation

b(1)

: effective operation as measured by a comparison of production with cost (as in energy, time, and money)

(2)

: the ratio of the useful energy delivered by a dynamic system to the energy supplied to it

3

: efficiency apartment

Synonyms

• edge
• effectiveness
• effectualness
• efficaciousness
• efficacity
• efficacy
• productiveness

Examples of efficiency in a Sentence

Because of her efficiency, we got all the work done in a few hours.

The factory was operating at peak efficiency.

A furnace with 80 percent fuel efficiency wastes 20 percent of its fuel.

The company is trying to lower costs and improve efficiencies.

Recent Examples on the Web

But think what made up this win: one set piece, one counter-attack, two stand-in centre-backs, plenty of tired legs, lots of defensive headers, a fair bit of game management, backs to the wall, spirit, nous, intelligence and efficiency. —Jack Pitt-Brooke, The Athletic, 3 Feb. 2025

This technology enhances safety and efficiency, enabling the train to adapt to changing conditions autonomously. —Kurt Knutsson, Cyberguy Report, Fox News, 2 Feb. 2025

Further, Rangan expects solid free cash flow generation, supported by Twilio’s aggressive cost reduction and efficiency measures. —Tipranks.com Staff, CNBC, 2 Feb. 2025

Lessons for the Present In a time when isolation and efficiency often trump human connection, Ted's story offers lessons for everyone. —Jason Phillips, USA TODAY, 2 Feb. 2025

Word History

Etymology

borrowed from Latin efficientia, from efficient-, efficiens "producing or giving rise to something, immediate (of a cause), efficient" + -ia -y entry 2

First Known Use

1633, in the meaning defined at sense 1

Phrases Containing efficiency

• efficiency apartment
• efficiency expert
• hyper-efficiency

Kids Definition

efficiency

noun

ef·​fi·​cien·​cy i-ˈfish-ən-sē 

plural efficiencies

1

: the quality or degree of being efficient

2

: efficient operation

3

: the ratio of the useful energy delivered by a machine to the energy supplied to it