What "cosigner" means in finance

A cosigner is a person who agrees to take on the legal obligation to repay a debt or loan in case the primary borrower defaults or is unable to repay the debt. The cosigner is equally responsible for the debt and may be required to repay the full amount along with any late fees or penalties. Cosigners are often used to help individuals with no credit or poor credit history to secure loans or other forms of credit. Lenders typically require a cosigner to have a good credit score and sufficient income to be able to pay back the loan in case the primary borrower fails to do so.