The term 'turn-by-turn' is a modern English compound that emerged with the advent of automotive and digital navigation. It employs a reduplicative structure, repeating the core action word 'turn' to emphasize the sequential, stepwise nature of the guidance. The preposition 'by', with its sense of proximity and succession, links these actions, creating a literal meaning of "proceeding from one turn to the next." This construction logically evolved from the basic physical meaning of 'turn'—a change in direction—into an abstract descriptor for a method of instruction that breaks down a continuous journey into a discrete, ordered series of maneuvers.

This is a fixed compound adjective formed by reduplication of the word 'turn', connected by the preposition 'by'. 'Turn' originates from Old English turnian/tyrnan (to turn, rotate), from Latin tornare (to turn on a lathe), from tornus (lathe), from Greek tornos (lathe, circle). 'By' originates from Old English bī (near, at, during), from Proto-Germanic bi.