'pesticide' originates from Latin, specifically the word 'pestis,' where 'pestis' meant 'plague' or 'pest,' combined with the suffix '-cide' meaning 'killer.'

'pestis' transformed into the French word 'pesticide,' and eventually became the modern English word 'pesticide' through Middle English.

Initially, it meant 'a killer of pests,' and this meaning has largely remained the same in modern usage.