A more thorough explanation:

Definition: Lex commissoria is a Latin term that means "forfeiture clause" or "cancellation clause." It was used in Roman law to refer to a clause in a contract of sale or pledge agreement that allowed the seller or creditor to cancel the contract if the buyer or debtor failed to pay the agreed price or debt on time.

Examples:

• A seller of a piece of land could include a lex commissoria clause in the contract of sale, which would give them the right to cancel the contract if the buyer did not pay the agreed price within the specified time.
• A creditor could include a lex commissoria clause in a pledge agreement, which would give them the right to take possession of the pledged property if the debtor failed to pay the debt on time.

These examples illustrate how lex commissoria was used in Roman law to protect the interests of sellers and creditors by giving them the right to cancel a contract or take possession of property if the buyer or debtor failed to fulfill their obligations.