'pestless' originates from the English word 'pest' combined with the suffix '-less', where 'pest' meant 'a destructive insect or other animal that attacks crops, food, livestock, etc.' and '-less' meant 'without'.

'pest' changed from the Latin word 'pestis' meaning 'plague' and eventually became the modern English word 'pest'.

Initially, 'pest' meant 'plague' or 'pestilence', but over time it evolved into its current meaning of 'a destructive insect or other animal'.