Shared top billing so could order cast around (2-7)
I believe the answer is:
co-starred
'shared top billing so' is the definition.
The definition and answer can be both to do with fundamental existence as well as being past participle verbs.
Maybe you can see an association between them that I can't see?
'order cast around' is the wordplay.
'around' indicates anagramming the letters.
'order'+'cast'='ordercast'
'ordercast' anagrammed gives 'CO-STARRED'.
'could' acts as a link.
Can you help me to learn more?
(Other definitions for co-starred that I've seen before include "Played the other leading role" , "Shared lead billing" .)