WordNet (r) 3.0 (2006):

kludge
    n 1: a badly assembled collection of parts hastily assembled to
         serve some particular purpose (often used to refer to
         computing systems or software that has been badly put
         together)

The Jargon File (version 4.4.7, 29 Dec 2003):

kludge


    1. /kluhj/ n. Incorrect (though regrettably common) spelling of kluge
    (US). These two words have been confused in American usage since the early
    1960s, and widely confounded in Great Britain since the end of World War
    II.

    2. [TMRC] A crock that works. (A long-ago Datamation article by Jackson
    Granholme similarly said: ?An ill-assorted collection of poorly matching
    parts, forming a distressing whole.?)

    3. v. To use a kludge to get around a problem. ?I've kludged around it for
    now, but I'll fix it up properly later.?

    This word appears to have derived from Scots kludge or kludgie for a common
    toilet, via British military slang. It apparently became confused with U.S.
    kluge during or after World War II; some Britons from that era use both
    words in definably different ways, but kluge is now uncommon in Great
    Britain. ?Kludge? in Commonwealth hackish differs in meaning from ?kluge?
    in that it lacks the positive senses; a kludge is something no Commonwealth
    hacker wants to be associated too closely with. Also, ?kludge? is more
    widely known in British mainstream slang than ?kluge? is in the U.S.


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

kludge

    /kluhj/ (From the old Scots "kludgie" meaning an
   outside toilet) A Scottish engineering term for anything added
   in an ad hoc (and possibly unhygenic!) manner.  At some point
   during the Second World War, Scottish engineers met Americans
   and the meaning, spelling and pronunciation of kludge became
   confused with that of "kluge".

   The spelling "kludge" was apparently popularised by the
   "Datamation" cited below which defined it as "An ill-assorted
   collection of poorly matching parts, forming a distressing
   whole."

   The result of this tangled history is a mess; in 1993, many
   (perhaps even most) hackers pronounce the word /klooj/ but
   spell it "kludge" (compare the pronunciation drift of mung).
   Some observers consider this appropriate in view of its
   meaning.

   ["How to Design a Kludge", Jackson Granholme, Datamation,
   February 1962, pp. 30-31].

   [Jargon File]

   (1998-12-09)