Heat past a simmer (4)
I believe the answer is:
boil
(Other definitions for boil that I've seen before include "Bubble up - inflamed swelling" , "Painful sore" , "7 in water" , "Cook in hot water" , "become inflamed" .)
I believe the answer is:
boil
(Other definitions for boil that I've seen before include "Bubble up - inflamed swelling" , "Painful sore" , "7 in water" , "Cook in hot water" , "become inflamed" .)