In philosophy, the word is loaned in its capacity as a technical term in Aristotelianism, in English usage following Alexander Grant,The Ethics of Aristotle (1857).
In classical thermodynamics, the term is coined as translating GermanWerk. Rudolf Clausius (1864) made a technical distinction betweenWerk andArbeit, both translating to English "work", and suggestedErgon for the purposes of the translation of his terminology into other modern languages.
The author has used the German wordWerk, which is almost synonymous withArbeit, but proposes the termErgon as more suitable for introduction into other languages. The Greek wordἔργον is so closely allied to the English word work, that both are quite well suited to designate two magnitudes which are essentially the same, but measured according to different units.
—T.A.H.", T. A. Hirst (trans.),The Mechanical Theory of Heat (1867), Appendix A. to Sixth Memoir [1864], "On Terminology" (translator's note),p. 254.