I highly recommend using aard 2 (Android only, available on f-droid) for dictionaries. I know it’s a click away on the internet, but local files are just faster, especially when you are looking up a number of words.

You can install a number of dictionaries with it. I like wikitionary (1.7 GB). I generally download such “public” data on the SD card to preserve space.

You can download using your browser but I’ll show how to use ftp, just for fun.

Downloading with FTP

The list of dictionaries from the website above gives the following address for english wikitionary

https://ftp.halifax.rwth-aachen.de/aarddict/enwiki/

ftp ftp.halifax.rwth-aachen.de

This will ask you to log in. Enter anonymous for the username and a password you don’t have to remember for the password (FTP is insecure, because it sends data in clear text. Therefore they allow anonymous log ins).

Change the dorectory

cd /aarddict/enwiki/

Now get the file

get enwiktionary-20210719.slob

Then mv to the SD card.