'augural' originates from Latin, specifically the word 'augurālis' (from 'augur'), where 'augur' meant 'one who interpreted omens (an official diviner)'.

'augural' changed from the Latin word 'augurālis' via Medieval Latin into Middle English and eventually became the modern English word 'augural'.

Initially it meant 'pertaining to an augur or the practice of augury,' but over time it evolved to the broader sense of 'relating to omens' or 'prophetic/portentous'.