Tutoring unit (6)
I believe the answer is:
lesson
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tutoring unit</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for lesson that I've seen before include "Class session or reading from Bible" , "Unit of instruction" , "Moral" , "warning message" , "See 1" .)