It was Merriam-Webster’s word of the day a while back, so I wrote this context clues worksheet on the verb regale. It is used both intransitively and transitively. I’m not sure high school students need to use it at all; if you think they do, or at least might, then it’s yours for the taking.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.