Frank or Stuart more than once plugs American news channel (4)
I believe the answer is:
anne
'frank or stuart' is the definition.
(Anne Frank and the Stuart monarch Queen Anne)
'more than once plugs american news channel' is the wordplay.
'more than once plugs' indicates a hidden word (two instances of the answer plugged into the clue).
'ANNE' can be found hidden inside 'american news channel'.
(Other definitions for anne that I've seen before include "British queen" , "One of two Henry VIII wives" , "'---- of Green Gables', novel by Lucy Maud Montgomery" , "--- Elliot, later Wentworth (J. Austen)" , "Queen in 1702-14" .)