What would dynamically-typed languages actually do if type enforcement was removed?

Question

I program in Python, which is a well-known dynamically typed language. I understand dynamic typing to mean mainly that "operations" (in a loose sense) in the language are either allowed or denied (raise an exception) based on the type of their operands, and that this type-checking is deferred as long as possible. My question is this: if that is what a fair characterization of dynamic languages, what would happen if the run-time type checking was removed?

It seems to me that if you want to make a meaningful distinction between a dynamically typed language like Python and an untyped language, you would have to define what actually would happen in the untyped language in situations in which the type system of a dynamic language would take action. For example, in Python, if I attempt to subtract an Integer from a String, e.g., "spam" - 5, I receive a TypeError. If that's what makes Python dynamically typed, what would an "untyped Python" do in that situation?