Great balls of fire (5)
I believe the answer is:
stars
'great balls of fire' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stars that I've seen before include "Heavenly bodies" , "Horoscope (colloq.)" , "Leading performers (with stripes?)" , "plays a leading role" , "''What is the ...? What is the ...? '' (Juno and the Paycock)" .)