Peaceableness is a synonym of tranquility.
As nouns the difference between tranquility and peaceableness
is that tranquility is an alternative spelling of lang=en while peaceableness is a state of being calm, or peaceful.
tranquility
English
Noun
(en-noun)
Usage notes
* More common spelling in the US; less common in the UK.
peaceableness
English
Noun
(-)
A state of being calm, or peaceful
Synonyms
* tranquility