Series about King George may cause acute annoyance (7)
I believe the answer is:
chagrin
'acute annoyance' is the definition.
(chagrin is annoyance or irritation)
'series about king george' is the wordplay.
'series' becomes 'chain' (chain is a kind of series).
'about' indicates putting letters inside.
'king george' becomes 'gr' (Georgius Rex).
'chain' placed around 'gr' is 'CHAGRIN'.
'may cause' is the link.
(Other definitions for chagrin that I've seen before include "Embarrassment - rich nag (anag)" , "Emotion" , "Disappointment, exasperation" , "Annoy" , "Arching with annoyed disappointment" .)