Main entry: still, tranquil, smooth, quiet, placid, unruffled
Definition: (of a body of water) free from disturbance by heavy waves
Usage: a ribbon of sand between the angry sea and the placid bay; the quiet waters of a lagoon; a lake of tranquil blue water reflecting a tranquil blue sky; a smooth channel crossing; scarcely a ripple on the still water; unruffled water
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