Frn: A term used in the investment and finance world to denote a financial instrument known as a floating rate note. A floating rate note (or FRN) is a debt obligation that comes with an interest rate that changes periodically depending on a predetermined index or benchmark. This makes it an attractive investment option for those looking to take advantage of market interest rate fluctuations. The ability of FRNs to adjust their rates means they can offer investors the potential for higher returns than traditional fixed-income investments.