Author unknown (4)
I believe the answer is:
anon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">author unknown</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 anon that I've seen before include "devoid of credit" , "Soon; unnamed" , "In a little while (informal)" , "soon to be written" , "Of unknown name (abbr)" .)