Astrophysicist — deGrasse Tyson (4)
I believe the answer is:
neil
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">astrophysicist degrasse tyson</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 neil that I've seen before include "-- Sedaka, US singer" , "- Armstrong, first man to walk on the moon" , "- Simon, US dramatist (Barefoot in the Park)" , "- Armstrong, first man to set foot on the Moon" , "1969 moon walker" .)