Meaning & Definition
adjective
not having enough of a specified quality or ingredient
The patient was diagnosed as deficient in vitamin D, requiring supplements.
lacking in some necessary quality or element
The plan was deficient in clarity, leading to confusion among team members.
insufficient in amount or degree; inadequate
Her knowledge of the subject was deficient, which affected her performance in the exam.
Etymology
Late Middle English: from Old French 'deficient' or from Latin 'deficient-' meaning 'failing.'
Common Phrases and Expressions
deficient in:
lacking a necessary quality or ingredient.
deficient amount:
an amount that is not sufficient.
deficient performance:
performance that is below expectations.
Slang Meanings
Not up to par.
That presentation was a bit deficient, no offense.
Slacking.
He's been deficient in his work lately.