That's not quite accurate. Common Lisp and Clojure are both lexically and dynamically scoped. In CL, things created with def* (defun, defparameter, defvar, etc...) are dynamic, while function arguments and things created with let are lexical[0]. In recent versions of Clojure, it's necessary to explicitly make a symbol dynamic with metadata.

[0] This is probably not entirely correct or complete, but should get across the general idea.