Split in bag appeared (3)
I believe the answer is:
gap
'split' is the definition.
(I've seen this in another clue)
'in bag appeared' is the wordplay.
'in' says the answer is hidden in the clue.
'GAP' is hidden within 'bag appeared'.
(Other definitions for gap that I've seen before include "Space (maybe for a year?)" , "Narrow space" , "Vacancy" , "Hiatus" , "Room" .)