The compound adjective 'steel-framed' is a modern construction from two ancient roots. 'Steel' originates from the Old English term for the hard metal, its use symbolizing ultimate strength and durability. 'Frame' derives from an Old English verb meaning to benefit or make ready, which over centuries specialized to mean constructing or giving shape to something. The suffix '-ed' is a versatile Germanic adjectival ending. Combined, these elements logically create a term that literally describes an object built with a skeletal support of steel, a concept which readily extends metaphorically to describe anything of inflexible and resilient constitution.

Structure: steel (material) + frame (structure) + ed (adjective suffix) steel: From Old English 'stēle', 'stȳle', of Germanic origin; the strong, hard alloy of iron and carbon. frame: From Old English 'framian' meaning "to be helpful, profit", related to 'fram' meaning "forward, bold". The sense evolved to mean "prepare, build, structure". ed: A suffix forming adjectives from nouns or verbs, indicating "having the characteristics of" or "provided with".