'expertly-assembled' originates from the combination of 'expertly' and 'assembled', where 'expertly' is derived from 'expert', meaning 'a person with a high level of knowledge or skill', and 'assembled' is the past participle of 'assemble', meaning 'to put together'.

'expertly' evolved from the Latin word 'expertus', meaning 'tried, tested', and 'assembled' comes from the Old French 'assembler', meaning 'to bring together'.

Initially, 'expertly' meant 'in a manner of an expert', and 'assembled' meant 'gathered together'. Over time, 'expertly-assembled' came to mean 'skillfully put together'.