Swill King George brought up, breaking wind (6)
I believe the answer is:
gargle
'swill' is the definition.
(thesaurus)
'king george brought up breaking wind' is the wordplay.
'king george' becomes 'gr' (Georgius Rex).
'brought up' is a reversal indicator (down clues only).
'breaking' is an insertion indicator.
'wind' becomes 'gale' (gale is a kind of wind**).
'gr' backwards is 'rg'.
'rg' placed within 'gale' is 'GARGLE'.
(Other definitions for gargle that I've seen before include "Use a throatwash" , "Wash out one's throat" , "Mouth/throat wash" , "Rinse throat with liquid without swallowing" , "Rinse the mouth and throat with mouthwash" .)