The word 'unimaginatively-used' is a compound formed from 'unimaginatively' (from 'unimaginative' + '-ly') and 'used' (past participle of 'use'). 'Unimaginative' comes from 'un-' (not) + 'imaginative' (having creativity), and 'used' comes from the verb 'use'.

'Unimaginative' developed in English from 'imaginative' (from Latin 'imaginativus'), with the prefix 'un-' added for negation. 'Used' is the past participle of 'use', which comes from Old French 'user', from Latin 'uti'. The compound 'unimaginatively-used' is a modern English formation.

Initially, the parts meant 'not creative' and 'employed', but together they evolved to mean 'employed in a way lacking creativity'.