edge

The word 'edge' descends directly from the Old English 'ecg', meaning the sharp side of a blade, a border, or a ridge. This Old English term is traced back to the Proto-Germanic 'agjo', which also gives rise to related words in other Germanic languages, such as German 'Ecke' (corner) and Old Norse 'egg' (edge). The Proto-Germanic root is further derived from the Proto-Indo-European 'h₂eḱ-', meaning 'sharp' or 'pointed', a root that also produced Latin 'acies' (edge, sharpness) and Greek 'akis' (point). The semantic journey from the concrete, physical concept of a 'sharp blade' to the more abstract notions of a 'border' or a 'competitive advantage' is a classic example of meaning extension based on the shared idea of a defining line or a critical point of contact.

This is a simplex word of Old English origin. The form 'edge' functions as a single, unanalyzable morpheme in modern English, carrying the core semantic concept of a boundary or sharp line.