Refuse to compromise on sick guests not changing (5,2,4,4)
I believe the answer is:
stick to ones guns
'refuse to compromise' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'on sick guests not changing' is the wordplay.
'changing' indicates anagramming the letters.
'on'+'sick'+'guests'+'not'='onsickguestsnot'
'onsickguestsnot' with letters rearranged gives 'STICK TO ONES GUNS'.
Can you help me to learn more?
(Other definitions for stick to ones guns that I've seen before include "Rely on own battery" , "refuse to give in" , "refuse to compromise?" , "not to crack!" , "Hold weapons tight" .)