The compound adjective 'steam-powered' is a modern English formation that directly combines two concrete nouns with a participial suffix to describe a specific technological function. The first element, 'steam', originates from the Old English word for vapor or hot breath, reflecting its fundamental nature as a visible gaseous state. The second element, 'power', traces back through Old French to the Latin verb posse (to be able), carrying the core sense of capacity or force. The suffix '-ed' is added to the noun 'power' to create a participial adjective meaning 'supplied with or driven by'. Thus, the term's literal logic is "supplied with the force of vapor," a concise description of machinery, notably from the Industrial Revolution, that converts the expansive energy of heated water vapor into mechanical motion.

Structure: steam (vapor) + power (energy) + ed (adjective suffix) - steam: From Old English stēam (vapor, hot exhalation), of Germanic origin. Functions as a noun root. - power: From Anglo-Norman poer, Old French pouoir, ultimately from Vulgar Latin potēre (to be able). Functions as a noun root. - ed: From Old English -ede, -ode, -ad, forming adjectives from nouns. Functions as a participial/adjectival suffix.