Bill ___ the Science Guy (3)
I believe the answer is:
nye
'bill the 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 "- - Bevan (NHS pioneer)" , "So-called government minister" , "-- Bevan, NHS founder" , "Welsh boy" , "Nickname of Aneurin Bevan" .)