the compound adjective 'steep-sided' is a modern english formation built from two ancient germanic roots. 'steep' originates from the old english stēap, which conveyed concepts of height and prominence, and by extension, a precipitous slope. 'side' derives from the equally old english sīde, referring to the flank or lateral boundary of an object. the suffix '-ed' is added to the noun 'side' to create an adjectival form, a productive pattern in english seen in words like 'winged' or 'bearded'. thus, the literal construction "having sides that are steep" directly and logically yields the modern geographical descriptor for landscapes with sharply inclined slopes.

Structure: steep (sharp slope) + side (edge) + ed (adjective suffix) - steep: from old english stēap (high, lofty, deep, prominent), functioning as an adjective describing a sharp slope. - side: from old english sīde (flank, side, the long part or aspect of something), functioning as a noun. - ed: from old english -ede, -od, -ad, a suffix used to form adjectives from nouns, meaning "having, provided with, characterized by".