deficient
Americanadjective
-
lacking some element or characteristic; defective.
deficient in taste.
-
insufficient; inadequate.
deficient knowledge.
noun
adjective
-
lacking some essential; incomplete; defective
-
inadequate in quantity or supply; insufficient
Other Word Forms
Etymology
Origin of deficient
First recorded in 1575–85; from Latin dēficient-, stem of dēficiēns “failing,” present participle of dēficere “to fail, run short, lack, weaken,” from dē- de- + ficere, combining form of facere “to do, make” ( see also do 1)
Explanation
Deficient means not enough or not adequate. Maybe you were deficient in caffeine that day. Maybe you were lacking in study time. But no doubt about it: you came up with a deficient number of correct answers on the physics test. If your new car fund remains deficient, you don't have enough money to buy a new car. This presents a problem if your current car is deficient in some way — say, it no longer has enough engine power to drive up a hill. You may not feel you have what it takes to get a job, but the reality is you will have to choose between indulging your own deficiencies in this area or the car's.
Vocabulary lists containing deficient
Tuesdays with Morrie
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!
Oh, No! Synonyms for "Bad"
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!
50 Words from Jane Austen's "Pride & Prejudice"
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.
Uday joins other clinicians and academics who have formed a group - ACT NOW Vitamin D - calling for the threshold at which you are classified as deficient to be raised.
From BBC ● Oct. 30, 2026
Lars Bochmann, a 50-year-old who has spent his entire professional life at the VW plant in Zwickau, told AFP that the agreement was "utterly deficient".
From Barron's ● Sep. 4, 2026
El Nino and a deficient monsoon are also emerging as economic risks, Citi Research said in a note.
From The Wall Street Journal ● Aug. 31, 2026
Remember less than 4% of Australians are deficient in vitamin C.
From Science Daily ● Aug. 27, 2026
“You know he is as ungainly within as without. A deficient, ill-tempered, lowering, stupid fellow.”
From "Great Expectations" by Charles Dickens
Random Word
Spin the wheel and learn a new word!
Get a wordDefinitions 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.
