Source : Free On-Line Dictionary of Computing

cdr
     
        /ku'dr/ or /kuh'dr/ [LISP] To skip past the first item from a
        list of things (generalised from the LISP operation on binary
        tree structures, which returns a list consisting of all but
        the first element of its argument).  In the form "cdr down",
        to trace down a list of elements: "Shall we cdr down the
        agenda?"  Usage: silly.  See also {loop through}.
     
        Historical note: The instruction format of the IBM 7090 that
        hosted the original LISP implementation featured two 15 bit
        fields called the "address" and "decrement" parts.  The term
        "cdr" was originally "Contents of Decrement part of Register".
        Similarly, "car" stood for "Contents of Address part of
        Register".
     
        The cdr and car operations have since become bases for
        formation of compound metaphors in non-LISP contexts.  {GLS}
        recalls, for example, a programming project in which strings
        were represented as linked lists; the get-character and
        skip-character operations were of course called CHAR and CHDR.
     
        [{Jargon File}]
     
        (2001-06-22)

CD-R
     
        {Compact Disc Recordable}