I'm looking forward to seeing what an English scholar says. I speak American and have never studied Middle English. But I'll take a guess.
- Vowchethe certainly means vouch.
- Gentilnese might mean respected position or respectability: Because He is a gentleman, we can trust him. (Ha!)
- Excuse might once have meant story. The modern English expressions What's your excuse? and What's your story? Are sometimes used to mean the same thing.
Now let's hear from someone who knows something!
Student or Learner