(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"
an object of dread or apprehension; "Germany was always a bugbear for France"; "A foolish consistency is the hobgoblin of little minds"--Ralph Waldo Emerson
an acute viral disease of the nervous system of warm-blooded animals (usually transmitted by the bite of a rabid animal); rabies is fatal if the virus reaches the brain
march aggressively into another's territory by military force for the purposes of conquest and occupation; "Hitler invaded Poland on September 1, 1939"
penetrate or assault, in a harmful or injurious way; "The cancer had invaded her lungs"
occupy in large numbers or live on a host; "the Kudzu plant infests much of the South and is spreading to the North"