Highly influential (7)
I believe the answer is:
seminal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">highly influential</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for seminal that I've seen before include "Rudimentary, influential" , "Menials giving rise to new beginnings" , "Major" , "Having strong later influence" , "Highy important" .)