"Clojure" is a programming language again based on the regular word "closure" but with some twists: The "j" is a tip of the hat to Java and the JVM where clojure is designed to run. This also has the nice property that the "zh" sound of the "s" in closure is also used with "j" sometimes (I think due to French). Thirdly I believe the "CL" letters of clojure are a tip to Common Lisp.
I'm not familiar with "Clozure CL" but the history is here: http://ccl.clozure.com/history.html