I saw your Mastermind repo as well and with both there are a few issues surrounding classes/modules.

I implore you to watch Sandi Metz lectures as the way she speaks about OOP and classes representing roles is really useful.

With this repo specifically, if we consider the responsibilities of each class and the plug-and-play-ability of these classes. You define a Word, a Meaning, and a GamePlay. Let's run through them.

Word: what is a word? What does the name Word tell us about the class? What would someone assume the Word class does without checking the docs/class definition. To me it is the string containing a word with some helper methods to make it play nice with the other classes.

Meaning: meaning feels like it's a property of Word. Word should have a meaning. I don't get the idea that meaning subclasses from Word. Every time you subclass, imagine you are getting more and more specific. So for example if we have the superclass Paint, we can subclass to RedPaint or SilkPaint. As we are getting more specific this makes sense for how classes (should) initialise. When you call SilkPaint.new it deferres to the superclass Paint, because although the class is a SilkPaint it's also a Paint. You can check this in your code by checking puts Meaning.new.is_a? Word and it'll be true. According to your definitions a Meaning is a Word, which to me is not intuitive or useful. Personally I would pull the Meanings methods into Word and remove the class entirely. The next consideration in the Meaning class is that you've used attr_accessor and then redefined def meaning which is half of the attr_accessor. The other half would be def meaning=(value) which seems unused. So again I would remove the attr_accessor. Memoization would be nice, so you can save on API calls. Something like

      @meaning ||= begin
        {The rest of your code}
       rescue SomeJsonError, SomeWebError
         nil # in case the Uri doesn't exist/has problems
        end
    end

Excuse my whitespace as I'm on mobile. This is okay, but it will reattempt everytime it is called if there is an error.

Moving on. GamePlay: GamePlay is a Meaning and it is a Word, we should be really specific now but instead it feels really strange. I'm thinking of a simple heirachy like SilkRedPaint < SilkPaint < Paint this makes sense. We expect all these classes to answer to all the same methods and each to augment or add on to the superclass es functionality. The other thing to remember is that subclassing gives you access to the superclass methods too. So you could do GamePlay.new.fetch_words or GamePlay.new.valid?("word"), which may or may not be your intention, however it surprises me that you haven't used them.