Answer, reaction (8)
I believe the answer is:
response
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">answer</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that answer can be written as response)</span><br/ ><br/ >'<span class="explanation-format__original">reaction</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that reaction can be written as response)</span><br/ ><br/ ></span>
(Other definitions for response that I've seen before include "'Answer, reply (8)'" , "counter" , "Reaction, reply" , "Preens so by way of answer" , "Press one for a reply" .)