Base Rate
Base rate is a rate (= level of interest) decided by the bank of a country that banks use when deciding how much to charge for lending money.
Base rate calculation is done by taking a lot of factors into consideration. These include the cost of deposits, the administrative costs borne by the bank, the profitability of the bank in the previous financial year and the unallocated overhead costs among other things. The bank also considers some other factors with stipulated weights while calculating the base rate of the lender. The term base rate is often used to refer to the base rate of individual financial institutions. If this is the case, reference will generally be to the base rate (from time to time) of a named institution. Typically this base rate will follow the Bank Rate, although there is no obligation to do so.
Cambridge dictionary. Cambridge University Press, Retrieved from: https://dictionary.cambridge.org/dictionary/english/base-rate
Koehler, J. J. (1996). The base rate fallacy reconsidered: Descriptive, normative, and methodological challenges. Behavioral and brain sciences.