Noah Webster
Serenity
SEREN'ITY, noun [Latin serenitas.]
1. Clearness and calmness; as the serenity of the air or sky.
2. Calmness; quietness; stillness; peace.
A general peace and serenity newly succeeded general trouble. Temple.
3. Calmness of mind; evenness of temper; undisturbed state; coolness.
I cannot see how any men should transgress those moral rules with confidence and serenity. Locke.
4. A title of respect.