tranquillity tranquillity /træŋˈkwɪlɪti/

noun

1. A disposition free from stress or emotion  ( placidity , quiet , repose , serenity , tranquility [ N. American] , tranquillity )
   a disposition free from stress or emotion
   
2. A state of peace and quiet  ( quietude , tranquility [ N. American] , tranquillity , quietness )
   a state of peace and quiet
   
3. An untroubled state; free from disturbances  ( tranquility [ N. American] , tranquillity , quiet )
   an untroubled state; free from disturbances