debenture
/dɪˈbentʃə(r)/noun
1- Brit. a long-term security yielding a fixed rate of interest, issued by a company and secured against assets〈英〉债券, 公司债券。
1.1
- （亦作debenture bond）N. Amer. an unsecured loan certificate issued by a company〈北美〉无担保的贷款证明。
词源
late Middle English （denoting a voucher issued by a royal household, giving the right to claim payment for goods or services）： from Latin debentur 'are owing' (from debere owe), used as the first word of a certificate recording a debt. The current sense dates from the mid 19th cent.