An issue of bonds with different maturities, as distinguished from an issue where all the bonds have identical maturities (term bonds).
Corporate bonds arranged so that specified principal amounts become due on specified dates. Related: Term bonds.
Corporate bonds arranged so that specified principal amounts become due on specified dates. Related: term bonds. 
Also called Instalment Bonds. Bonds which are issued on the same date but mature over a period of time, usually at regular intervals, so the issuer can spread the repayment to the investor
Bonds that mature in each year over a period of years, usually at varying interest rates,
Is an issuance of bonds which have different maturity dates for the principal. Often these bonds are issued on a year-by-year basis but there can be maturity gaps as well. 
A serial bond, sometimes called a serial note, is a debt security that matures and is payable at periodic dates during its term or life. Thus, it is repaid over a number of periods instead of one specific?maturity date.