The word "Folde" is the genitive singular of the Old English word "Foldan", which in turn is a feminine noun. It meaning can be translated to "of the earth", or simply "earth" or "land".
http://www.utexas.edu/cola/centers/lrc/eieol/engol-8-X.html
http://www2.thphy.uni-duesseldorf.de/~ansgar/languages.shtml
In that regards, it should perhaps be made clear as to why the word "Folde" was used by Tolkien, rather than leaving the page to mislead viewers that the "Folde" of Rohan (namely the Westfold and Eastfold as a collective) was invented by Tolkien and originally derived from Middle-Earth.
Start a discussion about improving the Folde page
Talk pages are where people discuss how to make content on Wikipedia the best that it can be. You can use this page to start a discussion with others about how to improve the "Folde" page.