'molding' originates from the English verb 'mold' (also spelled 'mould' in British English), ultimately influenced by Old French words such as 'moule'/'modele' meaning 'mold' or 'model', which trace back to Latin 'modulus' (a diminutive of 'modus') meaning 'measure' or 'manner'.

'mold' (Middle English forms like 'molden'/'molde') developed from Old French 'moule'/'modele' for a form used to shape materials; the English suffix '-ing' was later added to denote the material, result, or process, giving modern English 'molding'.

Initially it referred primarily to the hollow form or model used to shape material; over time it expanded to include the process of shaping and the shaped objects themselves, and in architecture came to denote decorative profiled strips (moldings).