'billboard' originates from the combination of 'bill' and 'board', where 'bill' meant 'a public notice' and 'board' referred to a flat surface for posting.

'billboard' changed from the earlier term 'bill board' used in the 19th century and eventually became the modern English word 'billboard'.

Initially, it meant 'a board for posting bills or notices', but over time it evolved into its current meaning of 'a large outdoor advertising board'.