'antiphilosophical' originates from the combining of two elements: the prefix 'anti-' from Greek 'anti' where 'anti-' meant 'against', and 'philosophical' from Latin/Greek roots related to 'philosophia' ('love of wisdom').

'antiphilosophical' was formed in modern English by prefixing 'anti-' to the adjective 'philosophical'. 'Philosophical' itself comes via Late Latin 'philosophicus' from Greek 'philosophia' (φιλοσοφία), which passed into Latin and then Middle English before becoming the modern adjective.

Initially it literally meant 'against philosophy' (i.e., opposed to 'philosophy' as an abstract discipline); over time its use has broadened to refer more generally to attitudes or approaches that reject or are hostile to philosophical/theoretical reasoning.