In science, thermo-dynamics (with a dash) was a term used from 1854 to 1868 to signify the newly developing science of the operation of generalized heat engines. The terms 'thermo-dynamic' (1849) and 'thermo-dynamics' (1854) were both coined by Irish physicist William Thomson. [1]

See also
● Thermodynamics (etymology)
● θ∆ics

References
1. (a) (a) Thomson, William. (1849). “An Account of Carnot’s Theory of the Motive Power of Heat; with Numerical Results Deduced from Regnault’s Experiments on Steam”, (127-203) Transactions of the Edinburgh Royal Society, xiv.; Annales de Chime, xxxv. 1852; in: Reflections on the Motive Power of Heat (ch. 4), J. Wiley, 1890.
(b) Thomson, William. (1854). Thermo-electric Currents, Preliminary 97-101, “Fundamental Principles of General Thermo-dynamics Recapitualted (pg. 232). Transactions of the Royal Society of Edinburgh, vol. xxi, part I.; read May.