The compound adjective 'strong-looking' is a relatively modern English formation, built from native Germanic roots. Its first element, 'strong', descends from the Proto-Germanic strangaz, carrying the core sense of tight, strict, and powerful. The second element, 'look', originates from the Proto-Germanic lōkōną, related to seeing and appearance. The suffix '-ing' is the productive adjectival suffix in English. The word's logic is transparently descriptive: it literally means "appearing in a manner that suggests strength," directly combining the concept of power with visual perception to create a straightforward descriptor of physical impression.

Structure: strong (having power) + look (appearance) + ing (adjective-forming suffix) - strong: From Old English strang, meaning powerful, firm, severe. In this compound, it conveys the quality of physical power. - look: From Old English lōcian, meaning to see, gaze, have a certain appearance. In this compound, it signifies the visual aspect or impression. - ing: A suffix from Old English -ende, -inge, used to form present participles and adjectives from verbs, here converting the verbal action of 'looking' into an adjectival state.