A more thorough explanation:

A convertible subordinated debenture is a type of debt instrument that can be converted into another security, such as stock. It is subordinate to other debts, meaning it is paid off after other debts are paid.

For example, a company may issue a convertible subordinated debenture to raise funds. The holder of the debenture can choose to convert it into stock at a later date, which can be beneficial if the stock price increases. However, if the company goes bankrupt, the holder of the debenture will only be paid after other debts are paid off.

Another example is a sinking-fund debenture, which is a type of debenture that is secured by periodic payments into a fund established to retire long-term debt. This type of debenture is often used by companies to ensure they have enough funds to pay off their debts when they come due.

In English law, a debenture is a company's security for a monetary loan. The security usually creates a charge on company stock or property. This means that if the company defaults on the loan, the lender can take possession of the stock or property to recover their funds.