single-level

The compound adjective "single-level" is a modern English formation that transparently combines two words of distinct Latin origins to describe a unitary flat plane. "Single" derives from Latin singulus, meaning "one" or "individual", which itself may trace back to a Proto-Indo-European root meaning "one". "Level" originates from Latin libella, a tool for checking horizontality, related to libra (a balance or scale), conveying the concept of an even, flat surface. The logic of the compound is direct and descriptive: "one" + "flat plane" creates a term used literally for architecture and metaphorically for computing systems that lack hierarchical complexity, maintaining a clear link from the ancient roots' core meanings of unity and balanced flatness to the modern technical and architectural senses.

Structure: single (one) + level (flat surface) - single: From Latin singulus (one, individual). Functional role: Adjective/quantifier meaning "one". - level: From Latin libella, a diminutive of libra (balance, scale). Functional role: Noun meaning "a flat, horizontal plane or position".