placidity placidity /pləˈsɪdɪti/

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 feeling of calmness; a quiet and undisturbed feeling  ( placidity , placidness )
   a feeling of calmness; a quiet and undisturbed feeling