'munch' originates from Middle English, specifically the word 'mounchen,' where 'mounchen' meant 'to chew with a closed mouth.'

'mounchen' transformed into the modern English word 'munch' through gradual phonetic changes.

Initially, it meant 'to chew with a closed mouth,' but over time it evolved into its current meaning of 'to chew food audibly or with a steady, continuous action.'