Tolkien generally uses the name 'Wilderland' rather than 'Rhovanion'.
Tolkien stated that Wilderland is an "invention .. based on wilderness .. Supposed to be the CS [&#8203;Common Speech&#8203;] name of Rhovanion (in the map, not in the [main] text), the lands east of the Misty Mountains (including Mirkwood) as far as the River Running."[REF] .