Involving two sides (9)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">involving two sides</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 bilateral that I've seen before include "Two-sided" , "involving more than one party?" , "Undertaken by two parties" , "involving two sides" , "Involving two parties" .)
(Another definition for bipartite that I've seen is " Involving two sides".)