Illegal copying (6)
I believe the answer is:
piracy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">illegal copying</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for piracy that I've seen before include "Robbery on the high seas" , "Maritime or commercial robbery" , "Crime" , "Copyright infringement" , "Act of plagiarism" .)