It was a camouflage paint scheme used on ships, mainly from 1914 to 1918. It consisted of a complex pattern of geometric shapes in contrasting colors, interrupting and intersecting each other. At first glance it seems like an unlikely form of camouflage, drawing attention to the ship rather than hiding it.
CB-1, The cruiser Alaska.
DD-541, The Yarnall.
USS Charles S. Sperry (DD-697) shown here in dazzle camouflage, June 1944.
HMS Argus displaying a coat of dazzle camouflage in 1918
"A British artist and naval officer, Norman Wilkinson, promoted a new camouflage scheme that was derived from the artistic fashions of the time, particularly cubism. Instead of trying to conceal the ship, it simply broke up its lines and made it more difficult for the U-boat captain to determine the ship's course."
Source: 1, 2 & 3