'smooth-surfaced' originates from Modern English as a compound of 'smooth' + 'surface' with the participial suffix '-ed' to indicate 'having a surface of that kind'.

'smooth' comes from Old English 'smōð' meaning 'smooth'; 'surface' entered English via Old French 'surface' from Latin 'superficies' (from 'super' 'above' + 'facies' 'face, appearance'). The compound form 'smooth-surfaced' is a modern descriptive formation in English combining these elements.

Initially the components meant 'smooth' and 'surface' respectively; combined with '-ed' they have long expressed 'having a smooth surface', and this basic descriptive meaning has remained consistent in modern usage.