Reader of secret messages (7)
I believe the answer is:
decoder
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">reader of secret messages</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 decoder that I've seen before include "The interpreter" , "Data converter" , "Eg, digital to analogue converter" , "One deciphers" , "This person decrypts" .)