Undefeated (8)
I believe the answer is:
unbeaten
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">undefeated</span>' is the definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for unbeaten that I've seen before include "Always winning" , "Never having lost" , "second to none" , "Always top" , "there's nothing better" .)