Bond certificate and Unsecured bond

Bond certificate noun - A certificate of debt (usually interest-bearing or discounted) that is issued by a government or corporation in order to raise money; the issuer is required to pay a fixed sum annually until maturity and then a fixed sum to repay the principal.

Unsecured bond and bond certificate are semantically related. In some cases you can replace phrase "Unsecured bond" with "Bond certificate", this phrases are similar.

Unsecured bond noun - The ability of a customer to obtain goods or services before payment, based on the trust that payment will be made in the future.

Bond certificate and unsecured bond are semantically related. You can use "Bond certificate" instead a noun phrase "Unsecured bond".