'unexcitingly' originates from English, formed from the negative prefix 'un-' (from Old English/Germanic 'un-') plus 'exciting' (the present participle of 'excite') and the adverbial suffix '-ly'. 'excite' originates from Latin, specifically the word 'excitare', where 'ex-' meant 'out' and 'citare' meant 'to rouse or call.'

'excite' changed from the Latin word 'excitare' through Old French (e.g. 'exciter') and Middle English forms (e.g. 'exciten'/'excite') and eventually became the modern English verb 'excite'; from that came the adjective 'exciting', then the negated adjective 'unexciting', and finally the adverb 'unexcitingly' by adding '-ly'.

Initially (in Latin), 'excitare' meant 'to rouse or call out', but over time it evolved into the modern English sense of 'to arouse emotion or interest'; 'unexcitingly' now carries the neutral/negative meaning 'in a manner lacking excitement'.