Daytime TV staple (4)
I believe the answer is:
soap
'daytime tv staple' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for soap that I've seen before include "It has detergent properties" , "Cleansing bar" , "TV programme - sudsy bar" , "Sudsy TV show?" , "type of TV programme" .)