"suicide flier," 1945, Japanese, literally "divine wind," from kami "god, providence" (see kami) + kaze "wind." Said to have been originally the name given in folklore to a typhoon which saved Japan from Mongol invasion by wrecking Kublai Khan's fleet (August 1281). The World War II attacks began in October 1944 off the Philippines. As an adjective from 1946.
As an aside, at war's end, the Japanese had, by actual count, a total of 16,397 aircraft still available for service, including 6,374 operational fighters and bombers, and if they had used only the fighters and bombers for kamikaze missions, they might have realized, additionally, 900 ships sunk or damaged and 22,000 sailors killed or injured. In fact, however, the Japanese had outfitted many aircraft, including trainers, as potential suicide attackers. As intelligence estimates indicated, the Japanese believed they could inflict at least 50,000 casualties to an invasion force by kamikaze attacks alone. [Richard P. Hallion, "Military Technology and the Pacific War," 1995]