REALLY long times (4)
I believe the answer is:
eons
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">really long times</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 eons that I've seen before include "Vast ages" , "Years and years" , "Times" , "Long periods of time - noes have it" , "Very long periods (US)" .)