I honestly think it depends on your school. For example, at my school, they break us into quartiles for our MSPE letters. Those are
Outstanding
Excellent
Very Good
Good
For our clinical rotations, we are graded honors (approx 25% of class), high pass (approx 25% of class), pass (50%). They seem to pull the same words though. For clerkships, I got high pass on, the descriptor was usually excellent. For honors, it was outstanding. I think they basically dont want to hurt anyone's feelings. It's weird but for us, very good implies below the average for the class.