'tranquility' definitions:

Definition of 'tranquility'

(from WordNet)
noun
A disposition free from stress or emotion [syn: repose, quiet, placidity, serenity, tranquillity, tranquility]
noun
An untroubled state; free from disturbances [syn: tranquillity, tranquility, quiet]
noun
A state of peace and quiet [syn: tranquillity, tranquility, quietness, quietude]