There is such a thing, but it has a different meaning than how I believe you used it.

You said "scripting languages have run-time type inference built in everywhere". I don't think that's true for most scripting languages. Inference refers to determining facts which were not explicitly provided, and usually implies a statically typed programming language where inference is done at compilation time. "Runtime type inference" might be used for, e.g., Python's Psyco project, where the just-in-time compiler infers properties about a particular variable (such that it's always an integer) and can therefore compile out boxing, unboxing, runtime type checks and so on.

Speaking of runtime type-checking, I inferred that that's what you meant when you said "runtime type inference". Type-checking IS something that happens at runtime almost everywhere in dynamic languages. It is also more closely associated with RTTI -- a dynamic_cast in C++ would not be termed type inference (the previous and new types are known), but a type check does occur at runtime.