Ghabn

or Ghubn, in Arabic غبن (laesio enormis), means literally to do wrong, cheat or misrepresent facts, resulting in injustice and possibly substantial deviation from market price. Ghabn in in Fiqh means weakness (انظر معجم مقاييس اللغة لابن فارس). specifically in price, that is getting less than what is given in an exchange. It has a relation to Riba because Riba is also giving more than the countervalue. In one Hadith the Prophet, pbuh, called a price difference (overcharge) Riba. Ghubn is also sometimes considered one of the types of Gharar, although the relation is distant.

References

• Minor and Excessive Ghabn: An Economic Analysis by MOHAMMAD AL-SUHAIBANI