Translation guide
Describes something that is flawed, broken, or not working properly. Japanese uses different words depending on whether the defect is physical, functional, or related to character.
Describing a product, machine, or object that has a manufacturing fault or is not working correctly.
Specifically refers to a defective product or item that fails quality standards. Common in manufacturing and retail contexts.
この不良品を交換してもらえますか。
Can I get this defective product exchanged?
Means 'has a defect/flaw'. Used for physical flaws in objects, systems, or even abstract things like plans.
この車には欠陥がある。
This car is defective.
Means 'is broken/out of order'. Used for machines or devices that are not functioning.
エアコンが故障している。
The air conditioner is defective.
Describing a person's character, reasoning, or behavior as flawed or lacking.
Also used for character flaws or deficiencies in a person's personality or reasoning.
彼の性格には欠陥がある。
His personality is defective.
Means 'has a fault/shortcoming'. Softer than 欠陥, often used for minor character flaws.
誰にでも欠点はある。
Everyone has defects.
Describing something that is incomplete or missing a component.
Means 'incomplete/imperfect'. Used when something is not fully formed or lacks essential parts.
その計画は不完全だ。
The plan is defective.
Means 'has an inadequacy/defect'. Often used in formal contexts for documents, systems, or preparations.
書類に不備があった。
The documents were defective.
English 'defective' is often translated as a noun phrase (不良品) or a verb phrase (故障している) rather than a direct adjective. Using 欠陥のある or 不完全な is possible but may sound stiff in casual speech.