'smooth-faced' originates from the combination of 'smooth' and 'face', where 'smooth' meant 'having an even and regular surface' and 'face' referred to the front part of the head.

'smooth' changed from Old English 'smōð' and 'face' from Middle English 'face', eventually forming the modern English word 'smooth-faced'.

Initially, it meant 'having a smooth surface on the face', but over time it evolved into its current meaning of 'having a face free from hair or wrinkles'.