Can you source most Americans working 2-4 jobs? I tried Googling around, and it seems the actual number of Americans with 2+ jobs was about 8mil, or 5%.
One out of twenty Americans is a far cry from “the average American.” But I’m open to being wrong. Just couldn’t find anything supporting that claim.
I think what you are probably actually after, based on your description/comments is a flash card app, not a dictionary app?
To that end, seems like a guy on the open source subreddit made a thread about it and built one that’s FOSS. Some other good suggestions in the thread, even if his solution isn’t what you’re after.
https://www.reddit.com/r/opensource/comments/14azw6d/an_open_source_flashcard_studying_system/