Lesson or lecture (5)
I believe the answer is:
class
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">lesson</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">lecture</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(academic class)</span><br/ ><br/ ></span>
(Other definitions for class that I've seen before include "High-quality" , "Set, category" , "Genus" , "Body of students" , "26 [ORDER]" .)