A person who shares responsibility for guaranteeing that someone will fulfill an obligation, such as paying back a loan.
From Latin 'co-' meaning 'together' and 'surety' from Old French 'surete', ultimately from Latin 'securitas' meaning 'security or safety'. A cosurety was a legal and financial term meaning joint guarantor.
Historically, cosureties were incredibly important—they represented trust networks where multiple wealthy people would guarantee a loan, making default nearly impossible because the lender could pursue any of them; it was a social enforcement mechanism before modern banking.
Complete word intelligence in one call. Free tier — 50 lookups/day.