Main entry: serene
Definition: completely clear and fine
Usage: serene skies and a bright blue sea
Main entry: calm, unagitated, tranquil, serene
Definition: not agitated; without losing self-possession
Usage: 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