tranche n[French, literally, slice, from Old French, from trenchier trancher to cut]
: a division or portion of a pool or whole: as
a : an issue of bonds derived from a pooling of like obligations that is differentiated from other issues esp. by maturity or rate of return
b : a bond series issued for sale in a foreign country
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.