Stalk (4)
I believe the answer is:
stem
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">stalk</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for stem that I've seen before include "Thwart; support" , "Slender vertical part, glass or plant" , "Slender upright part of wine glass" , "Ski turn and plant stalk" , "Basic skiing turn" .)