'expertly-built' originates from the combination of 'expertly' and 'built', where 'expertly' is derived from 'expert', meaning 'a person with a high level of knowledge or skill', and 'built' is the past participle of 'build', meaning 'to construct'.

'expertly' evolved from the Latin word 'expertus', meaning 'tried, tested', and 'built' comes from the Old English 'byldan', meaning 'to construct'.

Initially, 'expertly' meant 'with experience', and 'built' meant 'constructed'. Over time, 'expertly-built' came to mean 'constructed with a high level of skill'.