noun (plural serenities)

the state of being calm, peaceful, and untroubled:

落ち着き, 静穏; 晴朗, うららかさ(calmness)

e.g. an oasis of serenity amidst the bustling city.

(His/Your, etc., Serenity) a title given to a reigning prince or similar dignitary.

〖S-〗殿下, 妃殿下 (!敬称)

late Middle English: from Old French serenite, from Latin serenitas, from serenus ‘clear, fair’ (see serene).