Stalk; staunch (4)
I believe the answer is:
stem
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">stalk</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">staunch</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for stem that I've seen before include "Main part of noun or verb" , "It supports a plant" , "root" , "supporter of flag, for example" , "Tube" .)