What does efficient mean?
Efficient describes something — a person, process, machine, or organization — that achieves its purpose with little or no waste of time, money, energy, or effort. An efficient worker completes tasks quickly and competently; an efficient engine converts fuel into motion with minimal loss; an efficient system delivers results without needless steps. The word carries a broadly positive connotation of competence and economy, which is why it appears constantly in business, engineering, and environmental discussions, as in 'energy-efficient appliances' or 'a more efficient workflow.' It derives from the Latin efficere, meaning to accomplish or bring about, entering English in the late sixteenth century. Although efficient is sometimes used interchangeably with effective, the two are not identical: something can be effective without being efficient, succeeding in its aim but at great cost, while truly efficient work succeeds economically. This distinction makes the word valuable for anyone describing quality of performance rather than mere success.
adjectiveWorking or producing results with the minimum of waste, expense, or unnecessary effort; achieving a desired effect without wasted time or resources.
- (of a system, process, machine, or person) achieving maximum productivity with minimum wasted effort or expense.
- (dated or formal) causing or bringing about an effect; having the power to produce a result (as in 'the efficient cause').
"The new heating system is far more efficient than the one it replaced."
"She is an extremely efficient administrator who never wastes a minute."
"In philosophy, Aristotle distinguished the efficient cause from the material and final causes."
Efficient comes from the Latin efficere, 'to bring about' — so when you call something efficient, you're literally saying it gets things done.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of efficient
Efficient comes from the Latin verb efficere, meaning 'to bring about, accomplish,' formed from ex- ('out') plus facere ('to make or do'). English adopted it in the late sixteenth century, initially with the sense of 'causing or producing an effect' — a sense preserved in the philosophical phrase 'efficient cause.' By the eighteenth century it had developed its modern meaning of performing a task well with minimal waste, alongside its noun derivative efficiency.
Related word forms
How efficient is actually used
Neutral to positive in connotation; common in both everyday and technical contexts. In economics and engineering it often has a precise technical meaning (e.g., energy efficiency ratios), while in casual use it simply implies competence without waste.
Easily confused with efficient
Effective means producing the intended result at all, while efficient means producing that result with minimal waste of time, effort, or resources.