'zealously-assembled' originates from the combination of 'zealously' and 'assembled', where 'zealously' comes from 'zeal', meaning 'great energy or enthusiasm', and 'assembled' from 'assemble', meaning 'to gather together'.

'zealously' changed from the Old French word 'zel' and eventually became the modern English word 'zeal'. 'Assemble' comes from the Latin 'assimulo', meaning 'to bring together'.

Initially, 'zealously' meant 'with great energy', and 'assembled' meant 'gathered together'. The combined term retains these meanings, emphasizing the enthusiasm in the assembly process.