In “Potential Energy,” they wrote:
In 1853, William Rankine, in his “On the General Law of the Transformation of Energy”, introduced the term “potential energy”, as a terminological upgrade to the older terms: vis mortua (Leibniz, 1673), force morte (Diderot, 1769), or dead force.[1]
In 1860s, the term potential energy, in respect to a body of some height above the earth, as follows:
Ep = mgh
here m is the mass of the body, g is the gravitational constant, and h is the height of the body above the surface of the earth.
In 1867, Rankine, in his “On the Phrase Potential Energy”, explained the etymology of the term “potential energy”.