Better External Search Feature
In Settings -> Search, you can configure "custom search url when it comes from external" and also Split Search Setting to add multiple search actions.

For each action, you can setup some dicionary websites like:
Japanese: https://dictionary.goo.ne.jp/srch/all/%s
Korean: https://dict.naver.com/dict.search?dicQuery=%s
French: https://www.frdic.com/dicts/fr/%s

And then, if you read books, you can enable multi-window from Android platform, show EinkBro on the other s