Jackie_W,
I tried your method for renaming and adding the file to my \.kobo\dict folder. The “English-English” dictionary is available by the pull down menu, but when I select it I get the message “1 dictionary download pending; sync to install”. Rebooting the device didn’t seem to help.
Any ideas how to resolve this?
Update, I solved my own problem. If I don’t add the .zip on the end of the file when renaming it works. Also The iMac ( running Catalina) wouldn’t let me eject the reader without doing a Kobo sync. I did that through the web app and noticed it gave a message “loading dictionary”.
FYI I got lucky testing, by choosing “Visa”. It is not in the Kobo default dictionary, but was in the Webster 1913 dictionary. I didn’t know Visas were around in 1913!