Stars laid-back in carefree surroundings (6)
I believe the answer is:
galaxy
'stars' is the definition.
(I've seen this before)
'laid-back in carefree surroundings' is the wordplay.
'laid back' becomes 'lax'.
'in' indicates putting letters inside.
'carefree surroundings' becomes 'gay' (I can't explain this - if you can you should believe this answer much more).
'lax' going within 'gay' is 'GALAXY'.
Can you help me to learn more?
(Other definitions for galaxy that I've seen before include "e.g. The Milky Way" , "Component of starry universe" , "Collection of star systems (made of chocolate?)" , "Division of the universe" , "Large star system" .)