I couldn't find a good English
Wiktionary for PocketBook's default reader software, so I made one. Hopefully others find it valuable too.
I used the April 2025 StarDict-format EN-EN Wiktionary from
Reader Dict, converted it to XDXF (after some tinkering) using Markismus's
PocketBookDic, modified the formatting of the resulting XDXF file to improve its appearance in PocketBook's software, and then converted it to .dic with converter.exe.
I have attached the final .dic file, as well as the intermediate XDXF for anyone who might want to make their own modifications.
To use, copy the .dic file into the /system/dictionaries folder on your PocketBook device.