'antieducationally' originates from modern English, specifically the combination of the prefix 'anti-' + the adjective 'educational' + the adverbial suffix '-ly', where 'anti-' meant 'against', 'educational' came from 'education', and '-ly' forms an adverb meaning 'in the manner of'.

'education' ultimately comes from Latin 'educatio' (noun) and the verb 'educare' ('lead out' or 'bring up'); 'educational' developed as an adjective in English from 'education', and 'anti-' (from Greek anti- 'against') has long been used productively in modern English to create oppositional adjectives; adding '-ly' produced the adverb 'antieducationally'.

Initially the elements meant 'against' (anti-) and 'relating to education' (educational); over time the combined form has been used to describe attitudes, policies, or actions that work against or undermine education, and the adverb now describes doing something in that opposing/detrimental way.