efficiency
ih-FISH-un-see
/ɪˈfɪʃ.ən.si/
The ratio of useful output produced to the total energy or resources input into a process.
Higher efficiency means accomplishing the maximum amount of work while minimizing wasted heat, friction, or energy loss.
The story behind the word. From Latin 'efficientia', from 'efficere' (to bring about or accomplish). It entered engineering vocabulary during the Industrial Revolution to measure steam engine performance.
Word relationships
- productivity: 'Productivity' measures overall quantity output over time; 'efficiency' measures output relative to resource input without waste.
- inefficiency: Wasted effort, heat, or energy during a process.
Commonly confused with
- efficacy: 'Efficacy' means ability to work or produce an intended result; 'efficiency' means accomplishing it with minimal waste.
Word family
- efficient (adjective): Working productively without wasting energy.
- efficiently (adverb): In an efficient manner.
Collocations
- energy efficiency
- fuel efficiency
- operational efficiency
- thermal efficiency
Example sentences
- "Improving building insulation directly increases energy efficiency by keeping interior spaces warm without consuming excess heating fuel." Energy Policy
Memory hook
EFFICIENCY makes things EFFECTIVE without wasting energy. Maximum yield, minimum waste.
When not to use
Do not confuse with 'efficacy', which means producing a desired result regardless of resource cost.
Fun facts
- Traditional incandescent lightbulbs converted less than 5% of their energy into light, whereas modern LEDs achieve over 85% efficiency.
Related words
Explore more words
efficient, productivity, inefficiency, optimize, effective, optimization
Take your vocabulary further with LangBlitz
Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.