'esattamente' originates from Italian, specifically from the adjective 'esatto' plus the adverbial suffix '-mente', where 'esatto' ultimately comes from Latin 'exactus'.

'esatto' changed from Latin 'exactus' (the past participle of 'exigere', from 'ex-' + 'agere') through Vulgar Latin and Old Italian into modern Italian 'esatto'; the adverb 'esattamente' was formed by adding '-mente' (from Latin 'mente', 'mind') to create an adverb.

Initially, related Latin senses included 'driven out' or 'precisely determined' (from 'exigere'); over time the sense shifted and narrowed to the modern meaning 'exactly, precisely'.