Burst of applause (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">burst of applause</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 salvo that I've seen before include "Fusillade, volley" , "Unusual excuse" , "Simultaneous discharge of artillery" , "Outburst, as of applause" , "Barrage" .)