Steps:
1) Download vocabulary database, in your case de-en on this site (you need an mail adress for this)
https://www.dict.cc/?s=about:wordlist
2) Unpack and rename properly, ending csv.
3) Remove the header entries so that the first entry is a vocabulary entry.
4) Goto
https://www.mobileread.com/forums/sh...d.php?t=325203 and install pocketbook.pl properly, including perl and the tools mentioned there.
5) Use it as described on the dict.cc vocabulary list.
6) ... or look into your inbox here.