Definitions of exchange rate
the rate at which money from one country can be changed for the money of another country. For example, at the time of writing one Swiss Franc is worth 0.99 euro.
For each month and each currency, such exchange rate shall be the daily exchange rate in effect on the last day of the calendar quarter.
the rate at which one thing can be changed for another
The shares were issued at an exchange rate of one share of WCFC for each one share of PDC held.