As technologies and devices evolve, language must stay on its toes if we expect to understand each other when we talk about them. English speakers are particularly flexible at adapting to progress. They’re willing to coin new terms, modify old meanings, and allow words that are no longer useful to pass from common usage. “The etymologies of ‘motor’ and ‘engine’ reflect how language evolves to represent what’s happening in the world.”
“Motor” is rooted in the Classical Latin mōtor, which means “mover.” It first referred to propulsive force and, later, to the person or device that moved something or caused movement. “As the word came through French into English, it was used as 'initiator'", says Fuller. “A person could be the motor of a plot or a political organization.” By the end of the 19th century, the Second Industrial Revolution had dotted the landscape with steel mills and factories, steamships, and railways, and a new word was needed for the mechanisms that powered them. Rooted in the concept of motion, “motor” was the logical choice. By 1899, it had entered the vernacular as the word for Duryea and Olds’ newfangled horseless carriages.
“Engine” is from the Latin ingenium: character, mental powers, talent, intellect, or cleverness. In its journey through French and into English, the word came to mean ingenuity, contrivance, and trick or malice. “In the 15th century, it also referred to a physical device: an instrument of torture, an apparatus for catching game, a net, trap, or decoy.”