Old Icelandic work
I believe the answer is:
edda
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">old icelandic work</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 edda that I've seen before include "Scandinavian books of myths" , "mythological book" , "Icelandic poems" , "Ancient Icelandic writings" , "Ancient books" .)