Onyx Boox Poke5P User Manual page 58

You can import your own dictionary files and save them to
the designated storage path: sdcard\dicts\XXX;
Each dictionary has a corresponding folder. For example,
dicts\Advanced Chinese Dictionary
In dictionary Settings/Preferred Dictionary Setting, you can
check all available dictionaries. Up to 20 dictionaries are
supported.
When there are dictionaries installed, you can search
words in the search box. The lookup results are subject to
the words included in the dictionary. If you cannot find a
word, please change to another dictionary.
You can add found words to Vocabulary Builder to manage
in bulk.