Synonyms of deficient

deficient

adjective

di-ˈfi-shənt 

1

as in incomplete

lacking some necessary part

a diet deficient in calcium can lead to weak bones

Synonyms & Similar Words

• incomplete
• partial
• flawed
• half
• unfinished
• fragmentary
• damaged
• fragmental
• imperfect
• halfway
• impaired
• injured
• spoiled
• broken
• sketchy
• uncompleted
• marred
• unassembled

Antonyms & Near Antonyms

• complete
• perfect
• whole
• integral
• entire
• full
• intact
• unimpaired
• flawless
• undamaged
• unbroken
• uninjured
• finished
• unmarred
• completed

2

as in unacceptable

falling short of a standard

woefully deficient eyesight kept him out of military service

Synonyms & Similar Words

• unacceptable
• wrong
• poor
• lame
• bad
• flawed
• lacking
• unsatisfactory
• inferior
• terrible
• pathetic
• awful
• horrible
• substandard
• disastrous
• inadequate
• suboptimal
• defective
• subpar
• wretched
• brutal
• insufficient
• bastard
• ill
• dreadful
• crummy
• sour
• from hunger
• lousy
• wanting
• dissatisfactory
• paltry
• off
• bush
• useless
• wack
• rotten
• faulty
• below par
• punk
• worthless
• short
• gross
• miserable
• bush-league
• lesser
• abysmal
• deplorable
• atrocious
• detestable
• damnable
• common
• egregious
• shoddy
• unspeakable
• mediocre
• vile
• stinky
• horrendous
• execrable
• abominable
• flagrant
• valueless
• low-grade
• scanty
• gnarly
• reprehensible
• odious
• crappy
• meager
• sucky
• second-rate
• coarse
• bitchin'
• skimpy
• bum
• low-rent
• miserly
• trashy
• shabby
• cheesy
• stingy
• rubbishy
• sleazy
• junky
• mean
• spare
• villainous
• scurrilous
• counterfeit
• sham
• fake
• phony
• cut-rate
• skimp
• miscreant

Antonyms & Near Antonyms

• adequate
• satisfactory
• acceptable
• standard
• fine
• decent
• tolerable
• all right
• passable
• superior
• sufficient
• respectable
• OK
• excellent
• classical
• better
• great
• perfect
• divine
• classic
• splendid
• prime
• special
• superb
• wonderful
• superlative
• noble
• par excellence
• mean
• terrific
• marvelous
• top
• stellar
• first-class
• neat
• heavenly
• exceptional
• premium
• keen
• sensational
• average
• grand
• fabulous
• unsurpassed
• choice
• dandy
• capital
• swell
• slick
• sterling
• minimal
• fancy
• suitable
• useful
• high-grade
• borderline
• nifty
• A1
• mediocre
• banner
• worthy
• fair
• first-rate
• boss
• middling
• top-notch
• high-test
• supernal
• groovy
• crackerjack
• tip-top
• bang-up
• unexceptional
• satisfying
• gratifying
• jim-dandy
• so-so

3

as in lacking

not coming up to an expected measure or meeting a particular need

too deficient in common sense to be trusted to stay by himself

Synonyms & Similar Words

• lacking
• inadequate
• insufficient
• scarce
• low
• short
• wanting
• shy
• unacceptable
• unsatisfactory
• substandard
• sparse
• poor
• scanty
• meager
• skimpy
• lean
• scant
• stingy
• mere
• slender
• light
• minimum
• small
• spare
• slim
• bare
• skimp
• hand-to-mouth
• slight

Antonyms & Near Antonyms

• adequate
• sufficient
• enough
• abundant
• ample
• plentiful
• generous
• liberal
• copious
• bountiful
• enlarged
• bounteous
• plenteous
• satisfactory
• supplemented
• expanded
• overflowing
• tolerable
• rich
• large
• plenitudinous
• considerable
• substantial
• lavish
• super
• teeming
• luxuriant
• sizable
• abounding
• big
• oversize
• hefty
• jumbo
• largish
• king-size

Example Sentences

Recent Examples of deficient

The inspector found unclean conditions and deficient handwashing practices and sanitation methods, according to the spokesperson. — Harriet Ramos, Fort Worth Star-Telegram, 9 Sep. 2026

According to Wilkins Bratcher, plants that are deficient in magnesium may show signs of yellowing in their lower, older leaves and have a general lack of vitality because magnesium is the central element of the chlorophyll molecule. — Nadia Hassani, The Spruce, 7 Sep. 2026

Yet researchers have found that nearly a third of adults in the United States are iron deficient. — Anahad O’Connor, Washington Post, 27 Aug. 2026

Many people today have inherited and perpetuated this way of thinking without knowing it, including those who are deemed deficient by it. — Hilary Smith, The Conversation, 25 Aug. 2026