Would you rather be bitten by a poisonous snake or a venomous one? Which would you set down to dine upon? Me? I’d go for poisonous because there is a chance that other than the physical wound I’d be fine. I’m not eating it so the poisonousness doesn’t bother me it’s the venomous possibility that’s unknown.
Now if I’m going to eat roasted snake give me one venomous one – it might not be poisonous. I’ve had grilled rattler and it was good. But I’d not choose rattler for the first option there.
You see poisonous means you have to CONSUME it. Think of the cozy murder novels where the rat poison is put into the food. THAT’S poisonous. So a rattlesnake is not a poisonous snake it’s fine on the grill.
Venomous only happens when something ATTACKS you. Think of a bee sting. It itches and swells due to venom it injected. Now a rattler is a venomous snake and I’d skip it.
Many people use them interchangeably but they do not have the same meaning. So I hope if you were confused I cleared it up. When eating it poisonous is bad. When it’s attack you venomous is bad. Which is better depends on if what you want me to do with it.