Clipboard modification on copy by regex?

As I've already failed numerous attempts and still don't know what I'm doing lol - which method or scripting would you recommend?

I'd like to transform/replace certain words in the clipboard (i.e., abbreviating with medical terminology in a medical note, such as cardiology with cards or continue/continues/continued/continuing with cont) and automatically paste the transformed text. The vocab list is quite long, if that matters.