Again, with all due respect, that is not the only usage in finance.
Nominal (sometimes called stated) is also contrasted with effective. An effective interest rate includes the effects of compounding; a nominal (stated) interested rate does not.
If you invest $100 for one year at an effective (annual) rate of 6%, at the end of the year you will have $106 in your account.
If you invest $100 for one year at a nominal (annual) rate of 6% compounded semiannually, at the end of the year you will have $106.09 in your account.
Of course there is. You can have an effective rate for any length of time. If you can compound it, it’s an effective rate.
In my second example, above, the semiannual effective rate is 3% (= 6% ÷ 2).