'pester' originates from Middle French, specifically the word 'empestrer,' where 'en-' meant 'in' and 'pestrer' meant 'to entangle.'

'empestrer' transformed into the English word 'pester' during the 16th century.

Initially, it meant 'to entangle or ensnare,' but over time it evolved into its current meaning of 'to annoy persistently.'