One-time group of performers (6)
I believe the answer is:
'one-time' is the definition.
(I've seen this before)
'group of performers' is the wordplay.
'group of' indicates a hidden word (group of letters from the clue).
'FORMER' is hidden within 'performers'.
(Other definitions for former that I've seen before include "Ex-" , "The first of two, earlier" , "Past; first (of two)" , "Of an earlier time" , "not present" .)