'unenthusiastically-constructed' originates from the prefix 'un-' meaning 'not,' combined with 'enthusiastically,' derived from 'enthusiasm,' and 'constructed,' from Latin 'constructus,' meaning 'to build.'

'Constructed' changed from the Latin word 'constructus' and eventually became the modern English word 'constructed.'

Initially, 'constructed' meant 'to build or form,' and this meaning has largely remained the same in modern usage.