'smoothly-shaped' originates from the combination of 'smooth' and 'shape', where 'smooth' meant 'having an even and regular surface' and 'shape' referred to 'the external form or appearance of someone or something'.

'smooth' changed from Old English word 'smōð' and 'shape' from Old English 'sceap', eventually forming the modern English word 'smoothly-shaped'.

Initially, 'smooth' meant 'even surface', and 'shape' meant 'form', and this meaning has largely remained the same in modern usage.