'whistler' originates from the Old English word 'hwistlian', where 'hwist-' meant 'to make a sound'.

'hwistlian' transformed into the Middle English word 'whistlen', and eventually became the modern English word 'whistle'.

Initially, it meant 'to make a sound by blowing air', but over time it evolved into its current meaning of 'a person or thing that whistles'.