Stargazer (10)
I believe the answer is:
astronomer
'stargazer' is the definition.
(I know that stargazer can be written as astronomer)
This is all the clue.
(Other definitions for astronomer that I've seen before include "Stargazer" , "Moon starer (anag.)" , "Observer of space" , "Sky-at-night observer" , "scientist" .)