'apperceptionistic' originates from Modern English, specifically formed from the noun 'apperception' plus the adjectival suffix '-istic'. 'apperception' itself comes from Latin 'apperceptio', where 'ad-' (rendered as 'ap-' before 'p') meant 'to/toward' and 'percipere' (from which 'percept-' derives) meant 'to take, seize, perceive'.

'apperception' changed from Latin 'apperceptio' into English via scholarly and philosophical Latin usage; the modern English adjective 'apperceptionistic' was formed by adding the suffix '-istic' (via French/Latin adjective-forming patterns) to denote relation to or characteristic of apperception.

Initially, 'apperception' meant 'the taking in or thorough perceiving (of impressions)'; over time the term came to be used in psychology and philosophy for the process of assimilating new experiences into existing mental structures, and 'apperceptionistic' has come to mean 'relating to that assimilative process'.