There are in this extension, Dictionaries for Latin (a dead language), Mongolian, Welch, Portugal Pt ...
But not Brazilian Portuguese 😢... Ok then 👍🔟😂

simple but good add

I use it as a generic English dictionary and it works better then other extensions I've tried

The best addon i've ever used.

For anyone on zen browser having trouble installing dictionaries, you need to be in a workspace that doesn't have a default container before opening the extension settings!