How to make a selection from the explanatory dictionary?

Question

API

Hello.
In the title, I could not accurately formulate the question, since there are several of them, and they are vague.
Idea: the application randomly shows the word and gives an interpretation, then the word gets into the database of "already studied"
The idea is not new, and I have already seen something similar somewhere, but pre-prepared cards were submitted there.
I want the words to be displayed randomly, by filters, "medicine", "construction", "jurisprudence", for example, etc.
Actually, the questions are, are there dictionaries with an API that can be used to implement this? And how can you cut off the words in common use, all kinds of particles, pronouns, etc.?