Loud noise – period of prosperity (4)
I believe the answer is:
boom
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">loud noise</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">period of prosperity</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for boom that I've seen before include "Pole on film set" , "Spar - loud noise" , "It may protect harbour" , "Deep hollow sound" , "Deep sound; spar" .)