Efficient

adj. effective, done without waste (of time, resources, etc.)

Efficiency as a technical term may refer to:Energy efficiency, useful work per quantity of energyEnergy conversion efficiency, desired energy output per energy inputEnergy conservation, reducing the use of energyElectrical efficiency, useful power output per electrical power consumedFuel efficiency, converting energy in fuel to kinetic energy or workSpecific impulse, in propulsion systems, a measure of fuel-efficiencyVolumetric efficiency, in internal combustion engine designLighting efficiency, visible light from a light source per unit of energy, in lumens per wattMechanical efficiency, the effectiveness of a simple machine, mechanical advantage over ideal mechanical advantageThermodynamic efficiency, useful work per change in heatExergy efficiency, measure of 2nd-law themodynamic lossThermal efficiency, useful work per the higher heating value of the fuelRadiation efficiency, ratio of radiated power to power absorbed at the terminals of an antennaEfficiency (aerodynamics), for fixed wing aircraft the Lift-to-drag ratioEfficiency (economics), a general term, to capture the amount of waste or other undesirable featuresPareto efficiency, making one individual better off, without making any other individual worse offKaldor-Hicks efficiency, like a less stringent Pareto efficiencyAllocative efficiency, an optimal distribution of goodsThe optimisation of a social welfare functionEfficiency wages, paying workers more than the market rate for increased productivityEfficiency (statistics), a measure of desirability of an estimatorEfficiency ratio, expenses as a percentage of revenue, etc.Efficiency Movement, of the Progressive Era 1890-1932, advocated efficiency in the economy, society and governmentMaterial efficiency, compares material requirements between construction projects or physical processesTextual efficiency, density of a messageAlgorithmic efficiency, the speed and space requirements of a computer programQuantum efficiency, a measure of sensitivity of a photosensitive device: the percentage of photons hitting the photoreactive surface that will produce an electron–hole pair
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Adjective
1. being effective without wasting time or effort or expense; "an efficient production manager"; "efficient engines save gas"
(antonym) inefficient
(similar) businesslike
(see-also) competent
2. able to accomplish a purpose; functioning effectively; "people who will do nothing unless they get something out of it for themselves are often highly effective persons..."-G.B.Shaw; "effective personnel"; "an efficient secretary"; "the efficient cause of the revolution"
(synonym) effective
(similar) competent

adj. operative, in working order; efficient

adj. efficient, effective, done without waste (of time, resources, etc.)