'aristos' originates from Ancient Greek, specifically the word 'ἄριστος' (áristos), where the root conveyed the idea of being 'best' or 'most excellent'.

'aristos' passed into later languages as a combining element 'aristo-' and contributed to New Latin and French forms (for example Latin 'aristocratia' and Old French 'aristocratie'), which in turn produced English words like 'aristocracy' and 'aristocrat'.

Initially it meant 'best' in a literal superlative sense; over time the root produced words that shifted toward meanings related to social class and rule (e.g., 'rule by the best' → 'aristocracy').