All-star display? (6)
I believe the answer is:
cosmos
'all' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for cosmos that I've seen before include "Universe as an ordered whole" , "Everything that exists" , "Universe seen as a whole" , "The entire universe." , "well-organised world" .)