A slice, section or portion. | A distinct subdivision of a single policyholder's benefits, typically relating to separate premium increments. | A pension scheme's or scheme member's benefits relating to distinct accrual periods with different rules. | One of a set of classes or risk maturities that compose a multiple-class security, such as a CMO or REMIC; a class of bonds. Collateralized mortgage obligations are structured with several tranches of bonds that have various maturities.