definition for tranquility
Princeton's WordNet(2.67 / 3 votes)Rate this definition: 1  repose, quiet, placidity, serenity, tranquillity, tranquility(noun) a disposition free from stress or emotion. 2  tranquillity, tranquility, quiet(noun) an untroubled state; free from disturbances. 3  tranquillity, tranquility, quietness, quietude(noun) a state of peace and quiet.