'formally-assembled' originates from the English words 'formal' and 'assemble,' where 'formal' meant 'done in accordance with rules' and 'assemble' meant 'to gather together.'

'Formally-assembled' combines the adjective 'formal' with the past participle 'assembled' to describe something put together in a formal manner.

Initially, it meant 'gathered together in a formal way,' and this meaning has largely remained the same in modern usage.