Split asunder (2,3)
(Other definitions for in two that I've seen before include "Completely divided" , "divided up thus?" , "Asunder" , "simply split" , "apart" .)
(Other definitions for riven that I've seen before include "Split" , "Being cracked" , "Torn apart" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">split asunder</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 burst that I've seen before include "Split asunder" , "Explosion" , "Ruptured" , "Crack" , "Rope to catch cattle" .)