Synonyms of simmer down in English:

simmer down

See UK English definition of simmer


1‘he stormed out of the theatre in a rage but soon simmered down’

become less angry, cool off, cool down, be placated, let someone smooth one's ruffled feathers, contain oneself, control oneself, become calmer, calm down, become quieter, loosen up, settle, settle down
British quieten down
North American quiet down

get steamed up