The last time this was requested was 2019 and no one ever made it. All that exists that I could find is a command for urban dictionary.
I'd love to be able to type "!dictionary amalgam" and Nightbot would reply with the part of speech and the first definition from dictionary dot com like "noun. an alloy of mercury with another metal or metals."
Think of how fun it would be to also have "!wordoftheday"
If this is something you're willing to try, maybe leave a comment that you'll give it a try so people who find this thread late won't see how old this post is and think "someone else is probably working on it by now" and leave when they could have/would have done it.
That means if you're reading this right now and you could do it and there are no comments below, then you are the chosen one 👑