Neptune, say (6)
I believe the answer is:
planet
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">neptune say</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Neptune is an example)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for planet that I've seen before include "Celestial body orbiting around a star" , "Eg, Mars or Pluto" , "One orbiting star" , "Mars or Uranus" , "Celestial body orbiting round a star" .)