Chad
1950s: of unknown origin.
wiktionary
Uncertain; possibly from the English slang term chat(“ louse”). The word predates the chadless punch, which therefore cannot be its origin, [1] and a derivation from Scots chad(“ river gravel”) stated in some dictionaries is now thought to be nothing more than guesswork. [2]
From ch- + had, from ich + had.
chad (plural chads)
etymonline
chad (n.1)
also Mr. Chad, simple 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"), 1945, British, of unknown origin, a reaction to war-time shortages and rationing.
Chad
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. Related: Chadian.
chad (n.2)
"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. Perhaps it is not a coincidence that the word is identical to an English dialectal variant of chat, meaning "a dry twig; dry fragments among food."