(compile lib)
Compiles the namespace named by the symbol lib into a set of classfiles. The source for the lib must be in a proper classpath-relative directory. The output files will go into the directory specified by *compile-path*, and that directory too must be in the classpath.
user=> (compile (symbol "clojure.java.io")
clojure.java.io
user=> (compile (symbol "nonexistent.namespace")
FileNotFoundException Could not locate unexistent/namespace__init.class or unexistent/namespace.clj on classpath: clojure.lang.RT.load (RT.java:432)