Debenture

In the United States, a debenture is a type of long-term debt instrument not secured by physical assets or collateral.

Source: tatoeba (13565824)

As a fixed-income security, a debenture provides steady returns to cautious investors.

Source: tatoeba (13565826)

Madame Corre, who made the important decisions after her plodding husband had spent hours on the ledger, sold the family debentures and put the money into Dutch decurities.

Source: wiktionary

That the young Mr. Churchills liked—but they did not like him coming round of an evening and drinking weak whisky-and-water while he held forth on railway debentures and corporation loans. Mr. Barrett, however, by fawning and flattery, seemed to be able to make not only Mrs. Churchill but everyone else do what he desired.

Source: wiktionary