Regular TV series (3)
I believe the answer is:
set
This clue is a triple definition!
'regular' is the first definition.
(set can mean regular or fixed)
'tv' is the second definition.
(television set)
'series' is the third definition.
(both can mean a group of things)
(Other definitions for set that I've seen before include "Badger's burrow" , "Solidified" , "conventional" , "Create a puzzle" , "Complete collection" .)