A pitchfork was a long-handled fork with two to four long curved prongs and used especially for pitching hay.
In 2153, Captain Archer pointed out to T'Pol that when Vulcans landed on Earth, they were not chased with torches and pitchforks, however much Humans may have feared them. (ENT: "Horizon")
In 2268, Leonard McCoy insinuated that if Spock "landed someplace with a pitchfork", he could pass for the Devil. (TOS: "Bread and Circuses")
Later the same year, McCoy gave thanks to "pitchforks and pointed ears" after Spock had successfully beamed James T. Kirk aboard the USS Enterprise. (TOS: "Obsession")
In 2371, "Aunt Adah" used a pitchfork to hold Captain Kathryn Janeway and her crew at bay. (VOY: "Caretaker")