'mildew' originates from Old English, specifically the word 'mildeaw,' where 'mil-' meant 'honey' and 'deaw' meant 'dew.'

'mildeaw' transformed into the Middle English word 'mildewe,' and eventually became the modern English word 'mildew.'

Initially, it meant 'honey dew,' but over time it evolved into its current meaning of 'fungus.'