WCL is an acronym for Water Closet, a European euphemism for a room in which toilet facilities are located. Although W.C. is the much more common abbreviation.
WCL (Wade's CL) is also a Common Lisp implementation in a shared library by Wade Hennessey <wade@leland.Stanford.edu>. WCL is not a complete Common Lisp, but it does have the full development environment including dynamic file loading[?] and debugging. A modified version of GDB provides mixed-language debugging.