TV's "Science Guy" (3)
I believe the answer is:
nye
'tv's science guy' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nye that I've seen before include "Flock of pheasants" , "- - Bevan, 13 dn" , "So-called government minister" , "- - Bevan (politics)" , "Pheasant's nest" .)