NIRP
From ACT Wiki
Abbreviation for Negative interest rate policy.
NIRP is a policy of a central bank to keep (short-term) interest rates in the economy as low as it may. The central bank effects this by reducing its own interest charges for borrowings by financial institutions or its payments of interest on deposits taken from those institutions not merely to a 0% nominal rate but to some actually negative nominal rate.
Note that the real interest rate in the economy may be negative or positive irrespective of the nominal rate being negative, it being the difference between rate of inflation in the economy and interest rates paid or received.