The term "untyped" means anything that isn't statically typed (or just "typed"). This is because (static) types and dynamic "types" are two very different objects, and only the former is called "types" in programming language theory and formal languages in general.

I am well aware of clojure.spec, and it, as well as many other techniques employed in development, are probably among the reasons why types don't actually seem to have a big relative impact on correctness.