I haven't read the article, but when I say, in a certain context, that I don't consider clojure a Lisp, what I might mean is that clojure is not descendant from

I haven't read the article, but when I say, in a certain context, that I don't consider clojure a Lisp, what I might mean is that clojure is not descendant from the original McCarty lisp. You can trace Common Lisps or Emacs Lisps roots from MACLISP back to that. In such a context where the definition of "lisp" is sufficiently narrow, I might call languages like clojure and scheme "lisp like languages", or "distant dialects". It isn't any different from saying Linux is not Unix, but the various BSDs are. It doesn't really matter at all, and when used in the wrong context, such phrases can be confusing.