defective

1 of 2

adjective

de·​fec·​tive di-ˈfek-tiv 

1

a

: having a defect or flaw : imperfect in form, structure, or function

replaced a defective light switch

products manufactured with defective materials

defective intestinal absorption

a defective gene

b

dated, now offensive : having a physical or mental impairment

2

grammar : lacking one or more of the usual forms of inflection (see inflection sense 2)

Must is a defective verb.

defectively adverb

defectiveness noun

defective

2 of 2

noun

1

: something that is imperfect in form, structure, or function

… if we examine 18 items off the production line, we may be interested in the number of defectives we observe in the sample of size 18.

—Lloyd Jaisingh

2

dated, now offensive : a person having a physical or mental impairment

Synonyms

Adjective

• imperfect
• bad
• flawed
• faulty
• damaged
• broken

Examples of defective in a Sentence

Adjective

This computer is defective. I want my money back.

The disease is caused by a defective gene.

Recent Examples on the Web

Adjective

Progesterone promotes cell death among defective cells that could turn cancerous. —Jocelyn Solis-Moreira, Flow Space, 27 Oct. 2025

The family contends that the hotel knew, or should have known, that the property’s water heating system was dangerous and defective, accusing management of failing to inspect and maintain the temperatures. —Julia Marnin, Sacbee.com, 27 Oct. 2025

Noun

After two replacement phones (one defective, the next meant for another customer and locked) and 15 different Apple customer service representatives, Holland, a publicist in Wilmington, N.C., searched online for Jobs’s email address. —Washington Post, 23 Feb. 2021

Word History

Etymology

Adjective

Middle English defectif, defectyve "lacking, faulty, of poor quality," borrowed from Anglo-French defectif, borrowed from Late Latin dēfectīvus "lacking an inflectional form, imperfect, faulty," from Latin dēfectus, past participle of dēficere "to be lacking, run short, fail" + -īvus -ive — more at deficient

Noun

derivative of defective entry 1

First Known Use

Adjective

14th century, in the meaning defined at sense 1a

Noun

1562, in the meaning defined at sense 1

Rhymes for defective

• advective
• affective
• collective
• connective
• convective
• corrective
• detective
• directive
• effective
• elective
• infective
• injective

Kids Definition

defective

adjective

de·​fec·​tive

di-ˈfek-tiv

: lacking something essential : faulty

defective brakes

defectively adverb

defectiveness noun

Medical Definition

defective

adjective

de·​fec·​tive di-ˈfek-tiv 

: falling below the norm in structure or function

a defective heart valve

defectiveness

-nəs 

noun