'smoothly-formed' originates from the combination of 'smoothly' and 'formed', where 'smoothly' is derived from 'smooth', meaning 'even or without roughness', and 'formed' from 'form', meaning 'to shape or create'.

'smoothly' evolved from the Old English word 'smōth', and 'formed' from the Old French 'former', eventually becoming the modern English word 'smoothly-formed'.

Initially, 'smoothly-formed' meant 'shaped without roughness', and this meaning has largely remained the same in modern usage.