'nonvenomous' originates from the prefix 'non-' meaning 'not' and the word 'venomous' from Latin 'venenosus', where 'venenum' meant 'poison'.

'venenosus' transformed into the Old French word 'venimeux', and eventually became the modern English word 'venomous', with 'non-' added to indicate the absence of venom.

Initially, 'venenosus' meant 'full of poison', but with the prefix 'non-', it evolved to mean 'not full of poison'.