Dictionary.com

efficiency

[ ih-fish-uhn-see ]
/ ɪˈfɪʃ ən si /
Save This Word!
See synonyms for: efficiency / efficiencies on Thesaurus.com

noun, plural ef·fi·cien·cies.
the state or quality of being efficient, or able to accomplish something with the least waste of time and effort; competency in performance.
accomplishment of or ability to accomplish a job with a minimum expenditure of time and effort: The assembly line increased industry's efficiency.
the ratio of the work done or energy developed by a machine, engine, etc., to the energy supplied to it, usually expressed as a percentage.
QUIZ
WILL YOU SAIL OR STUMBLE ON THESE GRAMMAR QUESTIONS?
Smoothly step over to these common grammar mistakes that trip many people up. Good luck!
Question 1 of 7
Fill in the blank: I can’t figure out _____ gave me this gift.

Origin of efficiency

1585–95; <Latin efficientia, equivalent to efficient- (see efficient) + -ia-y3

OTHER WORDS FROM efficiency

non·ef·fi·cien·cy, nounsu·per·ef·fi·cien·cy, noun, plural su·per·ef·fi·cien·cies.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use efficiency in a sentence

British Dictionary definitions for efficiency

efficiency
/ (ɪˈfɪʃənsɪ) /

noun plural -cies
the quality or state of being efficient; competence; effectiveness
the ratio of the useful work done by a machine, engine, device, etc, to the energy supplied to it, often expressed as a percentageSee also thermal efficiency
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for efficiency

efficiency
[ ĭ-fĭshən-sē ]

The ratio of the energy delivered (or work done) by a machine to the energy needed (or work required) in operating the machine. The efficiency of any machine is always less than one due to forces such as friction that use up energy unproductively. See also mechanical advantage.
The ratio of the effective or useful output to the total input in any system.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK