Common LISP Object System (CLOS) An {object-oriented} extension to {Common LISP}, based on {generic function}s, {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)