'unbrokenness' originates from Modern English, specifically formed from the negative prefix 'un-' (from Old English 'un-' meaning 'not'), the adjective 'broken' (from Old English 'brocen'), and the suffix '-ness' (from Old English '-nes(s)e' meaning 'state, quality').

'unbrokenness' changed from older English compounding of 'un-' + 'broken' + '-ness'; 'broken' comes from Old English 'brocen' (past participle of 'brecan', 'to break'), passed through Middle English forms such as 'unbroke(n)nes(s)e', and eventually became the modern English 'unbrokenness'.

Initially, it meant 'the state of not being broken' (physical intactness), but over time it also acquired the extended meaning of 'a continuous or uninterrupted condition'.