Emily Dickinson Lexicon

SE-REN'I-TY, n. [Fr. serenité; L. 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 can not see how any men should transgress those moral rules with confidence and serenity. – Locke.
4. A title of respect. – Milton.