Crack (a cipher) (6)
I believe the answer is:
decode
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">crack a cipher</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for decode that I've seen before include "Do translation" , "Unscramble" , "Find hidden meaning" , "Explain" , "Convert a message into ordinary language" .)