It's turtles all the way down!

turtles.clj

(ns turtles
  (import [javax.script ScriptEngineManager]))

(defn -main [& args]
  (let [e (.getEngineByName (ScriptEngineManager.) "nashorn")]
    (.eval e
"var Clojure = Java.type('clojure.java.api.Clojure');
 var hello = Clojure.var('turtles', 'hello');
 hello.invoke();"
    )))

(defn hello []
  (println "Hello, World!"))

Requires at least Clojure 1.6 and JDK 8