Bond certificate and Secured 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.

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

Secured bond noun - A bond that is back by collateral.

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