Serenity (noun)

1. The state of being calm, peaceful, and untroubled.
2. A disposition free from stress or emotion.

Origin:

Middle english: from old french serenite, from latin serenitas, from serenus "calm, clear".

Examples:

1. She found serenity in the quiet of the forest.
2. The lake had a serene and tranquil atmosphere.
3. The yoga class was designed to help participants achieve serenity.
4. His face was etched with serenity, despite the chaos around him.
5. The garden was a place of serenity where she could escape from the stresses of everyday life.