'watcher' originates from Old English, specifically the word 'wæcce,' where 'wæccan' meant 'to be awake or keep watch.'

'wæcce' transformed into the Middle English word 'wacche,' and eventually became the modern English word 'watcher.'

Initially, it meant 'one who stays awake to keep watch,' but over time it evolved into its current meaning of 'a person who observes or keeps watch over something.'