'aristarchian' originates from Greek, specifically the name 'Aristarchos' (Latinized as 'Aristarchus'), where 'aristos' meant 'best' and 'arkhos' (or 'archos') meant 'ruler' or 'leader'.

'aristarchian' developed via Latin and New Latin scholarly usage referring to things 'of or relating to Aristarchus' (notably Aristarchus of Samothrace, a severe textual critic), then extended in English to describe a censorious or hypercritical attitude, yielding the adjective and noun forms in modern English.

Initially it meant 'of or relating to Aristarchus' (a proper name), but over time it evolved to mean 'severely critical or censorious' based on the reputation of certain historical figures named Aristarchus as harsh critics.