Serene (adjective)

1. Calm and untroubled; peaceful.
2. Having a clear sky.

Origin:

Middle english from old french serein, from latin serenus, from serenus 'clear, calm'.

Examples:

1. The morning was serene and beautiful.
2. The serene mountain lakes are a popular tourist destination.
3. Her serene demeanor was a source of comfort to everyone around her.
4. The serene blue sky was a perfect backdrop for the city skyline.
5. The serene forest was a peaceful place to go for a walk.