Bootstrapped ClojureScript refers to the idea that ClojureScript can compile itself. Evidently Lisp was the first and ClojureScript was probably the most recent to accomplish this: https://en.wikipedia.org/wiki/Self-hosting
But then there is also the concept that a ClojureScript app which is going to make use of a REPL needs to do some additional work to bootstrap the ClojureScript runtime. Normally when you ship a ClojureScript app you would employ Google Closure to concatenate everything into a single file which is loaded and evaluated. But if you want to work with individual files (one per Clojure namespace, which is important when you are working with a REPL), you need to avoid that and you need to set up things to use Google Closure's dependency management system (CLOSURE_IMPORT_SCRIPT, etc.). I have a blog post which attempts to explain the different meaning of "bootstrap" in this context: http://blog.fikesfarm.com/posts/2015-03-05-ambly-app-bootstr...
