Endorsement

Formal

Two definitions:

1. A modification to an insurance policy or loan agreement to reflect new commercial or contractual terms, OR
2. Signing the back of a cheque or Bill Of Exchange to transfer the ownership to someone else.

Real-world Example

A supplier receives a customer's cheque but owes money to a different vendor, so instead of depositing it, they endorse the cheque - sign the back - and pass it straight to that vendor.