Burgeon (6)
I believe the answer is:
sprout
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">burgeon</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 sprout that I've seen before include "something for Christmas dinner?" , "Begin to develop" , "Spring up like vegetable from Brussels" , "Develop new growth" , "Young shoot" .)