'disregard' originates from the prefix 'dis-' meaning 'not' and the word 'regard' from Old French 'regarder', meaning 'to look at'.

'regarder' transformed into the English word 'regard', and with the prefix 'dis-', it became 'disregard'.

Initially, it meant 'to not look at or consider', and this meaning has largely remained the same in modern usage.