Spiny succulent plant (6)
I believe the answer is:
cactus
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">spiny succulent plant</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 cactus that I've seen before include "Thorny desert plant" , "Succulent desert plant" , "Spiney plant of dry areas" , "Often prickly succulent plant native to arid regions" , "Prickly sort" .)