Definition - What does Co-Borrower mean?
Co-borrower is someone who accepts the responsibility of paying back a debt. Co-borrower is different from primary borrower as this person doesn’t typically receives direct benefit of the loan. Co-borrower may also be called a co-applicant or a co-signer.
Justipedia explains Co-Borrower
Co-borrower comes into play when the primary borrower is falling short on certain criteria. For example, a poor credit score can cause someone to need a co-borrower. If, for some reason, the primary borrower can't repay the loan, the co-borrower accepts the responsibility for repayment.