
English word serenity comes from Latin serenus
serenus (Latin)
(figuratively) Cheerful, glad, joyous.. Clear, fair, bright, serene, tranquil.. That clears the sky or brings fair weather.
serenitas (Latin)
(figuratively) favourable conditions. Serenity; fine weather.
sérénité (Middle French)
serenity (English)
A lack of agitation or disturbance.. A title given to a reigning prince or similar dignitary.. The state of being serene; calmness; peacefulness.