new-alist - an association list.

The list structure of alist is copied, and the elements of alist which are conses are also copied (as conses only). Any other objects which are referred to, whether directly or indirectly, by the alist continue to be shared.

(defparameter *alist* (acons 1 "one" (acons 2 "two" '())))
*alist*  ((1 . "one") (2 . "two"))
(defparameter *list-copy* (copy-list *alist*))
*list-copy*  ((1 . "one") (2 . "two"))
(defparameter *alist-copy* (copy-alist *alist*))
*alist-copy*  ((1 . "one") (2 . "two"))
(setf (cdr (assoc 2 *alist-copy*)) "deux")  "deux"
*alist-copy*  ((1 . "one") (2 . "deux"))
*alist*  ((1 . "one") (2 . "two"))
(setf (cdr (assoc 1 *list-copy*)) "uno")  "uno"
*list-copy*  ((1 . "uno") (2 . "two"))
*alist*  ((1 . "uno") (2 . "two"))