'unrestrictedness' originates from English, specifically the word 'unrestricted' + the noun-forming suffix '-ness', where the prefix 'un-' meant 'not' and 'restricted' is built on 'restrict' (from Latin roots).

'restrict' traces back to Latin 'restringere' (to bind tight) and Late Latin 'restrictus'; English formed 'restrict' from these roots. The negative prefix 'un-' comes from Old English 'un-' meaning 'not', and the suffix '-ness' comes from Old English '-nes(s)' used to form abstract nouns; these combined in Modern English to yield 'unrestricted' and then 'unrestrictedness'.

Initially the components meant 'not' + 'bound/tightened' + noun-forming '-ness'; together they have conveyed the state of 'not being restricted' since formation, and this core meaning remains in modern usage.