'blowhard' originates from the combination of 'blow' and 'hard', where 'blow' meant 'to boast' and 'hard' emphasized the intensity.

'blowhard' changed from the 19th-century American slang term 'blow' meaning 'to boast' and eventually became the modern English word 'blowhard'.

Initially, it meant 'to boast loudly', but over time it evolved into its current meaning of 'a person who boasts excessively'.