'unimaginatively' originates from the word 'unimaginative,' which is derived from the prefix 'un-' meaning 'not' and 'imaginative,' which comes from the Latin 'imaginativus,' meaning 'able to imagine.'

'unimaginative' transformed from the Latin word 'imaginativus' and eventually became the modern English word 'unimaginative' with the addition of the prefix 'un-'.

Initially, it meant 'not able to imagine,' and over time it evolved into its current meaning of 'lacking creativity or originality.'