What is Banker's Lien?

Legal Definition
A banker's lien is a legal right arise in many common law jurisdictions of a bank to exercise a lien over any property in the custody of the bank as security for the indebtedness of the customer to the bank.
-- Wikipedia
Legal Definition
A charge that lets a bank have claim on assets in the banks possession. It can take and sell this property if default should occur. They give notice of this but do not need to foreclose. The way it is enforced depends on the type of property.