Debenture

n. interest bearing bond indicating indebtedness; certificate indicating a tax refund (issued at a clearinghouse)

In finance, a debenture is a long-term debt instrument used by governments and large companies to obtain funds. It is similar to a bond except the securitization conditions are different. A debenture is usually unsecured in the sense that there are no liens or pledges on specific assets. It is however, secured by all properties not otherwise pledged. In the case of bankruptcy debenture holders are considered general creditors.
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Noun
1. a bond that is backed by the credit of the issuer but not by any specific collateral
(synonym) unsecured bond, debenture bond
(hypernym) bond, bond certificate
2. a certificate or voucher acknowledging a debt
(hypernym) legal document, legal instrument, official document, instrument
(classification) law, jurisprudence

n. debenture, interest bearing bond indicating indebtedness; certificate indicating a tax refund (issued at a clearinghouse)

(n.)
A writing acknowledging a debt; a writing or certificate signed by a public officer, as evidence of a debt due to some person; the sum thus due.
  

(n.)
A customhouse certificate entitling an exporter of imported goods to a drawback of duties paid on their importation.