(colloquial, pejorative) A crazy, possibly dangerous, person.
1992: Elmore Leonard, Rum Punch"He called the guy who owns the gun shop a 'whackjob' and said he's going to take him down if it's the last thing he does."
2003: Michael Graham, Redneck Nation: How the South Really Won the WarOne of America's most prominent Confederistas is Michael Hill, head whackjob at the looney League of the South—an obscure organization that has already declared southern cultural independence.
2004: Mark. St. Amant, Committed: Confessions of a Fantasy Football JunkieRonald Reagan took his oath as the fortieth president in American history and, three months later, took a bullet from some wackjob trying to impress the future star of The Silence of the Lambs.
