Pointless not including tip for students in class (6)
I believe the answer is:
lesson
'class' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for lesson that I've seen before include "Sermon or example" , "Moral" , "15 down period" , "Sermon or class session" , "Instructive experience" .)