Impressive, noteworthy (8)
I believe the answer is:
striking
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">impressive</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">noteworthy</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ ></span>
(Other definitions for striking that I've seen before include "stopping work" , "Prominent" , "Signal" , "Noticeable" , "Conspicuous" .)