Thickening agent (9)
(Other definitions for cornflour that I've seen before include "sauce thickener?" , "Basis of a mould" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">thickening agent</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for agar that I've seen before include "a newspaper rejected" , "What comes out of seaweed" , "found in the sea" , "contribution to culture?" , "part of culture?" .)