efficiency

[ih-fish-uh n-see] /ɪˈfɪʃ ən si/
noun, plural efficiencies.
1.
the state or quality of being efficient; competency in performance.
2.
accomplishment of or ability to accomplish a job with a minimum expenditure of time and effort:
The assembly line increased industry's efficiency.
3.
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.
4.
efficiency apartment.
Origin
1585-95; < Latin efficientia, equivalent to efficient- (see efficient) + -ia -y3
Related forms
nonefficiency, noun
superefficiency, noun, plural superefficiencies.
Examples from the web for efficiency
  • Or function at all with any semblance of efficiency, effectiveness, and accountability.
  • This is probably not a good plan from an efficiency stand point.
  • Energy efficiency is the unglamorous policy that nobody seems to be taking seriously, but it's got superb potential.
  • Propellers lost efficiency and thrust when they neared supersonic speeds.
  • Energy regulators plan to promote renewables and energy efficiency.
  • By the 1800s, steam-powered machines improved efficiency and textile mills opened.
  • Considering the age and significance of a house will help balance historic preservation and energy efficiency goals.
  • There are a few other tweaks that could be done to maximise efficiency, but i can't think of them right now.
  • Also discusses the improved efficiency of air-conditioners.
  • Describes the different fuel efficiency and body construction requirements for trucks and cars.
British Dictionary definitions for efficiency

efficiency

/ɪˈfɪʃənsɪ/
noun (pl) -cies
1.
the quality or state of being efficient; competence; effectiveness
2.
the ratio of the useful work done by a machine, engine, device, etc, to the energy supplied to it, often expressed as a percentage See also thermal efficiency
Word Origin and History for efficiency
n.

1590s, "power to accomplish something," from Latin efficientia (from efficientem; see efficient) + -cy. In mechanics, "ratio of useful work done to energy expended," from 1858. Attested from 1952 as short for efficiency apartment (itself from 1930).

efficiency in Medicine

efficiency ef·fi·cien·cy (ĭ-fĭsh'ən-sē)
n.

  1. The production of the desired effects or results with minimum waste of time, effort, or skill.

  2. A measure of effectiveness; specifically, the useful work output divided by the energy input in any system.

efficiency in Science
efficiency
  (ĭ-fĭsh'ən-sē)   

  1. 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.

  2. The ratio of the effective or useful output to the total input in any system.