The compound 'stepping-stone' is a transparent formation from native English elements. Its literal meaning, a stone placed in water to provide a dry foothold, dates to at least the 14th century, directly combining the action ('stepping') with the object ('stone'). The metaphorical sense, denoting a means of advancement or a stage in progress, emerged naturally from this concrete image. By the 17th century, it was commonly used to describe an intermediate position or action that facilitates reaching a more significant objective, perfectly encapsulating the logic of a physical aid translated into a conceptual one.

Structure: step (action) + ping (present participle suffix) + stone (object) - step: From Old English steppan, "to step, go," of Germanic origin. Functional role: Verbal root indicating the action of moving the foot. - ping: A modern English suffix forming the present participle or gerund of verbs. Functional role: Converts the verb 'step' into an adjective modifying 'stone'. - stone: From Old English stān, "stone, rock," of Germanic origin. Functional role: Noun root indicating the physical object.