Efficiency is avoiding a waste of time, effort, or resources. Many people have begun to use compact fluorescent light bulbs because of their greater energy efficiency.

Nowadays, efficiency often refers to energy efficiency, the effort to get more energy from existing resources: making cars that can go farther with less fuel, or appliances that do the same work with less electricity. But this noun isn't restricted to an environmental context. Efficiency can also simply be a measurement of what goes into a thing versus what comes out of it. A process with high efficiency requires only a little work to produce big results.

Definitions of efficiency

n skillfulness in avoiding wasted time and effort

“she did the work with great efficiency
unskillfulness resulting from a lack of efficiency
the efficient use of resources
Type of:
the state of being cognitively skillful

n the ratio of the output to the input of any system

figure of merit
a numerical expression representing the efficiency of a given system, material, or procedure
Type of:
the relative magnitudes of two quantities (usually expressed as a quotient)

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