Gen (4)
I believe the answer is:
info
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gen</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 info that I've seen before include "News" , "What's known" , "Intelligence (abbr)" , "Facts; knowledge gained" , "Data received and understood (abbr)" .)