Something else to consider: I believe the Kindle and Sony ereaders both use a version of the Oxford English Dictionary, and in my opinion this is superior to the Merriam Webster's dictionary supplied on the Kobo. It is something I sorely missed when I switched from Sony to Kobo, and I wish Kobo would spend a bit more on licensing a better dictionary.
It is possible to use your own custom dictionaries on the Kobo (
https://www.mobileread.com/forums/sho...d.php?t=232883), but you need a suitable source dictionary to convert to the Kobo format.