As always, please provide context. These words do not mean the same thing, but they might both work in some situations, so we need to see the context to answer.
As always, please provide context. These words do not mean the same thing, but they might both work in some situations, so we need to see the context to answer.
Both of these words are clearly defined in the Dictionary at the top of the page; therefore, no, you wouldn’t normally use “bystander” in your example.