1. Marked by, or suggestive of, utter peacefulness and undisturbed repose or quietude: There was a sereneness that settled on the farm after the cyclone passed by and things returned to normal.
2. Characterized by the absence of emotional agitation: There was an eerie sense of sereneness filling the city square after the rioters left.
3. A reference to the windless and stormless conditions of the weather: At the cottage, Brad enjoyed the sereneness of the calm summer skies with only puffy clouds overhead.