1911 Encyclopædia Britannica/Monadnock

MONADNOCK, a term derived from Mount Monadnock in New Hampshire, U.S.A., to denote the "isolated remnants of hard rock which remain distinctly above their surroundings in the late stages of an erosion cycle" (T. C. Chamberlin, R. D. Salisbury). Examples are frequently found where a hard pipe of igneous rock surrounded by softer rock is gradually exposed by the washing away of the softer rock and becomes a conspicuous feature of the landscape, forming a volcanic "neck," and finally, in the later stages of erosion, a stump. The Peak Downs, Queensland, furnish many examples, and Mato Tepee, Wyoming, is a remarkably conspicuous instance of this type of formation.