efficient
- 01 B2 Upper Intermediate
working 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.
Simple“The new secretary is very efficient and finishes her reports much faster than the last one.”
In context“By 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.
SynonymsAntonyms - 02 B2 Upper Intermediate
using very little fuel, electricity, or money to do a job.
relating to the ratio of useful output to the total energy or resources consumed.
Simple“We bought an efficient washing machine that uses less water and electricity.”
In context“The engineering team focused on developing a more fuel-efficient engine to meet the new environmental regulations.”
Synonymseconomicalfuel savingAntonyms - 03 C2 Proficiency
the actual thing or person that makes something happen.
acting as the immediate agent or cause that produces a specific effect or result.
Simple“The court had to decide if the driver's actions were the efficient cause of the accident.”
In context“In 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.
Synonyms
efficient vs effective — Effective means a thing works to get the job done, while efficient means it works without wasting time, money, or energy.
efficient vs sufficient — Efficient is about how well a task is performed with minimal waste, while sufficient is simply about having enough of something to meet a need.
Usage efficient way · efficient management · efficient manner
“The bio-hybrid technology could eventually help make AI systems and next-generation computers far more energy efficient.”
“Meanwhile, the fridges themselves have been made more energy efficient.”
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.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.