V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

CLOS
       Common LISP Object System (LISP)


The Free On-line Dictionary of Computing (30 December 2018):

Common LISP Object System
CLOS

    (CLOS) An object-oriented extension to Common
   LISP, based on generic functions, multiple inheritance,
   declarative method combination and a meta-object protocol.
   A descendant of CommonLoops and based on Symbolics
   FLAVORS and Xerox LOOPS, among others.

   See also PCL.

   ["Common LISP Object System Specification X3J13 Document
   88-002R", D.G.  Bobrow et al, SIGPLAN Notices 23, Sep 1988].

   (1994-11-30)