'autonomousness' originates from Greek, specifically the word 'autonomos', where 'autos' meant 'self' and 'nomos' meant 'law'; it was formed in English by combining the adjective 'autonomous' with the suffix '-ness' to make a noun meaning 'the state of being autonomous'.

'autonomousness' derived from the adjective 'autonomous' (from Greek 'autonomos' via Latin and later French/English usage) combined with the Old English/Proto-Germanic suffix '-ness' (used to form abstract nouns); 'autonomos' (Greek) -> Latin/Medieval uses of 'autonomous' -> English 'autonomous' -> modern English 'autonomousness'.

Initially, the Greek root conveyed the idea of 'self-law' or 'self-rule'; over time this developed into the modern English meaning of 'the condition or quality of being self-governing or independent.'