calm (part of speech: verb)
peaceful (part of speech: adjective)
unexcitable (part of speech: adjective)
content (part of speech: adjective)
No tear she shed, no word she said, and she ordered her face to be serene.
- "The Unknown Sea", Clemence Housman.
The monk smiled, slowly and brilliantly, and there was a look of such serene
confidence in his face that the other was amazed.
- "Dawn of All", Robert Hugh Benson.
Just as they rose from table, in came four Serene
Highnesses, who had also been stripped of their territories by the fortune of war, and were come to spend the Carnival at Venice.
- "Candide", Voltaire Commentator: Philip Littell.