Night-sky sight (4)
I believe the answer is:
star
'night-sky sight' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for star that I've seen before include "Screen idol" , "Astronomer - dreamer" , "Top-of-the-bill artist" , "may be a dwarf or a giant" , "Main attraction" .)