efficient
Americanadjective
-
performing or functioning in the best possible manner with the least waste of time and effort; having and using requisite knowledge, skill, and industry; competent; capable.
a reliable, efficient assistant.
- Synonyms:
- effectual
-
satisfactory and economical to use.
Our new air conditioner is more efficient than our old one.
-
producing an effect, as a cause; causative.
-
utilizing a particular commodity or product with the least waste of resources or effort (usually used in combination).
a fuel-efficient engine.
adjective
-
functioning or producing effectively and with the least waste of effort; competent
-
philosophy producing a direct effect; causative
Usage
What are other ways to say efficient? A person or a thing that is efficient performs or functions in the best possible manner with the least waste of time and effort. But efficient isn’t quite the same as effectual, efficacious, or effective! Find out why on Thesaurus.com.
Other Word Forms
Etymology
Origin of efficient
First recorded in 1350–1400; Middle English, from Middle French, from Latin efficient- (stem of efficiēns ), equivalent to ef- ef- + fic-, combining form of facere “to make, do 1 ” + -ent- -ent
Explanation
The adjective efficient describes function and use with the least amount of waste and most economy. When you want to define the adjective efficient, it's a good idea to say as much as you can in as few words as possible because to be efficient is to be economical and avoid waste in actions or uses. The word comes from the Latin efficientem which means "work out" or "accomplish." Synonyms of efficient are effective, productive, and competent.
Vocabulary lists containing efficient
List 1
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Labor Day Lexicon: Words That Put You To Work
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Essential English Vocabulary, List 1
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The ancestors of monitor lizards, also known in Australia as goannas, lost osteoderms entirely – likely because their active lifestyle and efficient bodies functioned better without the additional weight.
From Science Daily • May 21, 2026
Although AI is becoming more energy efficient, more people are using it every day, and higher demand products like AI agents are on the horizon.
From Salon • May 21, 2026
Its Ram truck brand is once again offering a popular V-8 engine called the HEMI, reversing a Tavares-era decision to kill the engine in favor of a more efficient, more powerful V-6.
From The Wall Street Journal • May 21, 2026
Governments should not be permitted to search broad groups of innocent people merely because technology makes doing so efficient.
From Slate • May 20, 2026
“Reynard, be a good lad and tell S.Q. you wish to surrender. This will be the most efficient course. You are soon to be captured, regardless.”
From "The Mysterious Benedict Society" by Trenton Lee Stewart
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
