runaway

The compound "runaway" is a transparent combination of two native English elements, "run" and "away," forming a phrasal verb turned adjective and noun. The Old English ancestor of "run," rinnan, originally carried a sense of fluid motion, which evolved into the general concept of rapid movement on foot. Coupled with "away," from the Old English phrase on weg meaning "on one's way," the compound literally describes the act of fleeing or departing hastily. Over time, this literal sense of a fleeing person or animal broadened to encompass metaphorical applications, such as processes or situations that are escaping from normal limits or control, like a "runaway inflation" or a "runaway success."

Structure: run + away - run (verb): From Old English rinnan, iernan (to flow, run). Its functional role is as the core verb, indicating the action of moving swiftly. - away (adverb): From Old English aweg, on weg (on one's way, from this or that place). Its functional role is as a directional particle modifying the verb, indicating movement from a place or state.