efficient
adj.-
1 productive and organized (adj.) B2 Upper Intermediateworking in a well-organized way without wasting time or energy.
performing or functioning in the best possible manner with the least waste of time and effort.
ExampleThe new secretary is very efficient and finishes her reports much faster than the last one.
ExampleBy reorganising the workflow, the manager created a more efficient system that reduced overtime costs by twenty percent.
PitfallThe new medicine is very efficient at curing the flu.The new medicine is very effective at curing the flu.Use 'effective' for something that produces a result, and 'efficient' for something that works without wasting resources.
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2 energy or resource usage (adj.) B2 Upper Intermediate Technical Scienceusing very little fuel, electricity, or money to do a job.
relating to the ratio of useful output to the total energy or resources consumed.
ExampleWe bought an efficient washing machine that uses less water and electricity.
ExampleThe engineering team focused on developing a more fuel-efficient engine to meet the new environmental regulations.
- economical
- fuel saving
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3 causing an effect (adj.) C2 Proficiency Formal Technical Lawthe actual thing or person that makes something happen.
acting as the immediate agent or cause that produces a specific effect or result.
ExampleThe court had to decide if the driver's actions were the efficient cause of the accident.
ExampleIn legal theory, the efficient cause is the primary agency that sets a chain of events in motion, leading directly to the injury in question.
UsageCommonly found in the phrase 'efficient cause' in legal or philosophical texts.
- causative
- instrumental
1398, “making,” from Old French, from Latin efficientem, nominative efficiēns, participle of efficere (“work out, accomplish”) (see effect). Meaning “productive, skilled” is from 1787. Efficiency apartment is first recorded 1930, American English.
- Adjectiveefficient
- Adverbefficiently