Eighth sign of the zodiac (7)
I believe the answer is:
scorpio
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eighth sign of the zodiac</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for scorpio that I've seen before include "7 [SIGN OF THE ZODIAC]" , "Zodiacal sign" , "A heavenly body" , "Astrological sign" , "star group" .)