History chapters (4)
I believe the answer is:
eras
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">history chapters</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for eras that I've seen before include "Periods of time" , "Long and distinct periods of history" , "At least two times" , "Epochs" , "Periods, ages" .)