Perennial (9)
I believe the answer is:
evergreen
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">perennial</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for evergreen that I've seen before include "Holly, for example" , "song that's been popular for a long time" , "Ivy, perhaps" , "Always popular" , "Scots pine, perhaps" .)