'automaticness' originates from Modern English, formed from the adjective 'automatic' plus the noun-forming suffix '-ness'; 'automatic' ultimately comes from Greek 'automatos', where 'auto-' meant 'self' and 'matos' (or the root related to it) meant 'moving'.

'automatic' changed from Greek 'automatos' to Latin 'automaticus', then via French (e.g. 'automatique') into Middle/Modern English as 'automatic'; the English suffix '-ness' (from Old English '-nes(s)e') was added to form 'automaticness'.

Initially it meant 'self-moving' or 'acting of itself' (from Greek), but over time it evolved to the modern senses of 'operating by itself' and, metaphorically, 'done without conscious thought'.