وَكُلُّ مَا أَوْجَبَ نُقْصَانَ الثَّمَنِ فِي عَادَةِ التُّجَّارِ فَهُوَ عَيْبٌ
Translation: Anything that reduces the price according to merchants’ established custom qualifies as a defect.
The legal measure is not personal disappointment alone. Relevant commercial custom and expert valuation help identify a qualifying defect.
1. A concealed electronics failure that depresses the market value.
2. A manufacturing flaw in fabric that lowers its trade value.
3. Disliking a previously known color does not by itself make an item defective.