The Milky Way, for one (6)
I believe the answer is:
galaxy
'the milky way for one' is the definition.
(milky way is a kind of galaxy)
This is all the clue.
(Other definitions for galaxy that I've seen before include "Large star system" , "Assemblage of stars" , "many stars" , "Splendid assemblage" , "System of stars - assembly of talent" .)