Group is ready (3)
I believe the answer is:
set
I believe this is a double definition.
'group' is the first definition.
(set is a kind of group)
'is ready' is the second definition.
('set' can be similar in meaning to 'ready')
(Other definitions for set that I've seen before include "Sink below the horizon" , "Become solid like jelly" , "exclusive party" , "Group of things of the same kind that belong together" , "Where they're filming" .)