Parts of a serial (8)
I believe the answer is:
episodes
'parts of a serial' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for episodes that I've seen before include "Incidents or events as in a story" , "So espied in parts of stories" , "Occurrences in a series" , "Sections of a serial" , "Instalments" .)