'negational' originates from Latin, specifically the word 'negatio', where 'negare' meant 'to deny'.

'negational' changed from Middle English/Old French words such as 'negacioun'/'negation' and eventually became the modern English word 'negational' by the addition of the adjectival suffix '-al' to 'negation'.

Initially, the root referred to the act or concept of 'denial' ('negation'), but over time it developed the adjectival sense of 'relating to or expressing negation' embodied in 'negational'.