A very thin, minor fracture or fissure in a surface, often used to describe imperfections in materials.

एक बहुत पतली, छोटी दरार या裂缝, जो अक्सर सामग्रियों में दोषों को दर्शाती है।

English Usage: The old table had a hairline crack that didn't affect its stability.

Hindi Usage: पुरानी मेज़ में एक hairline crack थी जो इसकी स्थिरता को प्रभावित नहीं करती थी।