Synonyms of serene

Adjective

1. calm, unagitated, serene, tranquil, composed (vs. discomposed)

usage: not agitated; without losing self-possession; "spoke in a calm voice"; "remained calm throughout the uproar"; "he remained serene in the midst of turbulence"; "a serene expression on her face"; "she became more tranquil"; "tranquil life in the country"

2. serene, clear (vs. cloudy)

usage: completely clear and fine; "serene skies and a bright blue sea"

Definition and meaning of serene (Dictionary)