You might add
KOReader it uses the Coolreader 3 Engine (cr3) for .epub, .mobi and a number of other ebook formats. Koreader supports Stardict dictionaries that can be found on the internet. There are a number of translation dictionaries, also. You can now select and lookup words from within the definition popup window, as well.
It also works by a long press on the word you want a definition for.
Luck;
Ken