(of a body of water) free from disturbance by heavy waves; "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"
any large scale calamity (especially when thought to be sent by God)
any epidemic disease with a high death rate
a serious (sometimes fatal) infection of rodents caused by Yersinia pestis and accidentally transmitted to humans by the bite of a flea that has bitten an infected animal