Flight in which one's surrounded by celebrities (6)
I believe the answer is:
stairs
'flight' is the definition.
(I've seen this in another clue)
'one's surrounded by celebrities' is the wordplay.
'one' becomes 'i' (Roman numeral).
'surrounded by' is an insertion indicator.
'celebrities' becomes 'stars' (star can mean a famous person).
'i' going into 'stars' is 'STAIRS'.
'in which' is the link.
(Other definitions for stairs that I've seen before include "Means of ascent/descent" , "Series of steps" , "A flight of indoor steps" , "A set of rising steps" , "Ascending flight of steps" .)