mezzanine
adjective [ before noun ]
/ˈmetsəniːn/ /ˈmezə-/ ukus/ˈmezənin/ FINANCE
relating to borrowed money that must be paid back by a company or organization with financial problems after paying its senior debt (= debt that must be paid before others)but before paying its junior debt (= debt that will be paid after others):
She has invested in senior bonds and mezzanine bonds.
The use of mezzanine debt in buyouts has increased substantially in recent years.