The compound adjective 'wall-size' is a modern formation following the productive English pattern of noun-noun compounding. The first element, 'wall', traces back to a Latin term for a defensive rampart, which evolved in Old English to denote any substantial vertical structure defining a boundary or space. The second element, 'size', originates from a legal term for an ordinance or fixed measure, later generalized to mean physical dimensions. The logic of the compound is transparently descriptive: it literally means "of the dimensions (suitable for) a wall," directly linking the ancient concept of a large, imposing structure ('wall') with the concept of standardized measurement ('size') to create a term denoting something made on a grand, architectural scale for display.

Structure: wall (barrier) + size (dimension) - wall: From Old English 'weall', meaning a rampart or defensive structure, of Latin origin ('vallum' - palisade, rampart). In this compound, it functions as a noun modifier specifying location or purpose. - size: From Old French 'sise', a shortening of 'assise' (session, ordinance, measure), ultimately from Latin 'assidere' (to sit beside). In this compound, it functions as a head noun indicating dimension or measurement.