It’s a word we teachers bandy about enough that students have certainly heard it, perhaps even ad nauseum. This context clues worksheet on the noun rigor should help clear up its meaning for our students, and supply the corollary benefit of helping them understand just what it is we seek to do in the classroom.
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.