Preliminary (12)
I believe the answer is:
introductory
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">preliminary</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for introductory that I've seen before include "Basic, preliminary" , "Opening" .)