'uninterruptedness' originates from English, specifically formed from the negative prefix 'un-' + the adjective 'interrupted' with the noun-forming suffix '-ness', where 'un-' meant 'not' and '-ness' formed a noun meaning 'state or condition'.

'interrupt' changed from Latin the verb 'interrumpere' (inter- 'between' + rumpere 'to break'), passed into Old French and Middle English as forms like 'interrompre'/'interrupte', and eventually became the modern English 'interrupt'; 'interrupted' is the past/adjectival form and 'uninterruptedness' was later formed in Modern English by prefixing 'un-' and adding '-ness'.

Initially, Latin 'interrumpere' meant 'to break between' (to break or burst in the middle); over time 'interrupt' came to mean 'to cause a break or halt in continuity', and 'uninterruptedness' developed to denote the current meaning 'the condition of not being interrupted; continuousness'.