Serenity
Etymology
From Latin "serenus," which described the sky and weather: “clear, fair, cloudless.” Serenity was a meteorological word before it was an emotional one — the state of a sky with no storm in it. The metaphor is so apt we barely notice it: a serene person has clear skies within.
noun · /suh-REN-i-tee/
A calm, untroubled clearness of mind.
What it names
Use it for inner weather that has gone still and bright — peace that feels like a cloudless day inside.
Example
There was a serenity to her the morning after she finally made the decision.
Related idea
Against equanimity: serenity describes the calm itself (the clear sky); equanimity is the steadiness that keeps you level whatever the weather — composure under provocation, not just peace in easy times. You can lose serenity to bad news and still hold your equanimity.
See also