The compound adjective "two-foot-high" is a modern English formation built entirely from native Germanic elements. "Two" derives from the Proto-Indo-European root dwo-, signifying duality. "Foot" originates from PIE ped-, referring to the foot, which evolved into a standard unit of length. "High" comes from PIE keuk-, meaning to arch or be bent, later generalized to signify tallness. The compound logically combines these elements in a descriptive, hyphenated form to specify a precise linear dimension, following the common English pattern for adjectival measurements.

Structure: two (number) + foot (unit) + high (measurement) - two: From Old English 'twā', meaning the number after one. Germanic origin. - foot: From Old English 'fōt', meaning the terminal part of the leg or a unit of measurement. Germanic origin. - high: From Old English 'hēah', meaning of great vertical extent. Germanic origin.