Fifth-brightest star in the night sky (4)
I believe the answer is:
vega
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fifth-brightest star in the night sky</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for vega that I've seen before include "First magnitude star" , "Star in Lyra; grassy plain (Spanish)" , "Bright star of constellation Lyra" , "Brightest star of constellation Lyra" , "Gave turn to a star" .)