'skillfully-built' originates from the combination of 'skillful' and 'built', where 'skillful' comes from the Old English 'sceolful', meaning 'full of skill', and 'built' from the Old English 'byldan', meaning 'to construct'.

'skillful' changed from the Old English 'sceolful' to the modern English 'skillful', and 'built' evolved from 'byldan' to 'built'.

Initially, 'skillful' meant 'full of skill', and 'built' meant 'to construct'. The combined term 'skillfully-built' retains the original meanings, emphasizing construction with skill.