Recurring series of changes (5)
I believe the answer is:
cycle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">recurring series of changes</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for cycle that I've seen before include "Recurring series of changes" , "Sequence of events that repeats" , "Series of events; bike" , "Pedal-powered transport" , "Series; sequence" .)