serene

Short definition from Wiktionary

Adjective

1. 1
   Calm, peaceful, unruffled.
2. 2
   Without worry or anxiety; unaffected by disturbance.
3. 3
   Fair and unclouded (as of the sky); clear; unobscured.
4. 4
   Used as part of certain titles, originally to indicate sovereignty or independence.

Verb

1. 1
   To make serene.

Noun

1. 1
   Serenity; clearness; calmness.
2. 2
   A fine rain from a cloudless sky after sunset.

Proper noun

1. 1
   A female given name from English. A rare variant of Serena.