1917, noun, verb, and adjective, from French camoufler, Parisian slang, "to disguise," from Italian camuffare "to disguise," which is of uncertain origin, perhaps a contraction of capo muffare "to muffle the head." Probably altered in French by influence of French camouflet "puff of smoke, smoke puffed into a sleeper's face" (itself of unknown origin) on the notion of "blow smoke in someone's face." The British navy in World War I called it dazzle-painting.
Since the war started the POPULAR SCIENCE MONTHLY has published photographs of big British and French field pieces covered with shrubbery, railway trains "painted out" of the landscape, and all kinds of devices to hide the guns, trains, and the roads from the eyes of enemy aircraft.
Until recently there was no one word in any language to explain this war trick. Sometimes a whole paragraph was required to explain this military practice. Hereafter one word, a French word, will save all this needless writing and reading. Camouflage is the new word, and it means "fooling the enemy." [Popular Science Monthly, August 1917]