Tea at home limits King George's discomfiture (7)
I believe the answer is:
chagrin
'discomfiture' is the definition.
(I've seen this before)
'tea at home limits king george's' is the wordplay.
'tea' becomes 'cha' (cha is a type of tea).
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'limits' means one lot of letters goes inside another (limit can mean to contain or block off).
'king george' becomes 'gr' (Georgius Rex).
'cha'+'in'='chain'
'chain' going around 'gr' is 'CHAGRIN'.
(Other definitions for chagrin that I've seen before include "Annoyance at having been humiliated" , "Annoy" , "Feeling of annoyance and embarrassment" , "Arching with annoyance and embarrassment" , "Disappointment, exasperation" .)