efficiency

ih-FISH-un-see /ɪˈfɪʃ.ən.si/
nounB2IELTSTOEFLGREGMAT
academicbusinesstechnical

The state or quality of achieving maximum productivity with minimum wasted effort, expense, or energy.

Measures the ratio of useful output to energy/resource input.

The story behind the word. From Latin 'efficientia', from 'efficiens' (producing, effecting), derived from 'efficere' (to work out, accomplish). In classical Latin it meant producing an effect, but during the Industrial Revolution it evolved into an engineering term for useful energy output.

Word relationships

  • productivity: Productivity measures total output, while efficiency measures output relative to wasted resources.
  • streamlining: Streamlining is the process of removing friction, whereas efficiency is the measure of the result.
  • inefficiency: Inefficiency is wasting time, energy, or resources.

Commonly confused with

  • efficacy: Efficacy is the power to produce a desired result; efficiency is doing so without wasting resources.

Word family

  • efficient (adjective): Achieving maximum productivity with minimum waste.
  • efficiently (adverb): In an efficient manner.

Collocations

  • energy efficiency
  • fuel efficiency
  • improve efficiency
  • maximum efficiency

Idioms & expressions

  • peak efficiency

Example sentences

  • "Improving heat pumps increases energy efficiency, drastically lowering heating bills across winter." Energy engineering
  • "Modern manufacturing plants optimize process efficiency to minimize material waste and carbon emissions." Manufacturing

Memory hook

E-FISH-ENCY = Fast like an efficient fish gliding through water without drag. Maximum output, minimum waste.

When not to use

Do not confuse with 'effectiveness', which means getting the right result regardless of how much energy was spent.

Fun facts

  • Traditional incandescent light bulbs converted less than 5% of their energy into light, representing poor energy efficiency compared to modern LEDs.

Related words

reduce, adapt

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