A herb (5)
I believe the answer is:
thyme
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a herb</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that thyme is a type of Herb)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for thyme that I've seen before include "Shrub - herb" , "Shrubby herb" , "Aromatic culinary herb; sounds like occasion" , "Plant of the mint family" , "Ingredient in cooking" .)