Spruce or sycamore
I believe the answer is:
tree
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">spruce</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">sycamore</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ ></span>
(Other definitions for tree that I've seen before include "Holly, perhaps" , "eg Lime" , "''I think that I shall never see / A poem lovely as a ...'' (Kilmer)" , "Plant with bark" , "Ash or elm, for example" .)