chad (n.1)
also Mr. Chad, graffiti drawing of a head peering over a fence or wall, with the caption, "Wot, no ______?" (the U.S. version usually had "Kilroy was here"), in reaction to shortages and rationing, 1945, British, of unknown origin.
Chad (n.2)
African nation, former French colony (Tchad), independent since 1960, named for Lake Chad, which is from a local word meaning "lake, large expanse of water." An ironic name for such a desert country.
chad (n.3)
"hanging flap or piece after a hole is punched in paper," a word unknown to most people until the 2000 U.S. presidential election (when the outcome hinged on partially punched paper ballots in some Florida counties), attested by 1930, of unknown origin.