Penetrating (8)
I believe the answer is:
incisive
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">penetrating</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for incisive that I've seen before include "Of speech, sharp and clear" , "(Of action) quick, direct" , "Intelligently analytical and clear-thinking" , "Analytical, concise" , "Clear and penetrating, as of speech" .)