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

hash collision
 n.

    [from the techspeak] (var.: hash clash) When used of people, signifies a
    confusion in associative memory or imagination, especially a persistent one
    (see thinko). True story: One of us [ESR] was once on the phone with a
    friend about to move out to Berkeley. When asked what he expected Berkeley
    to be like, the friend replied: ?Well, I have this mental picture of naked
    women throwing Molotov cocktails, but I think that's just a collision in my
    hash tables.? Compare hash bucket.


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

hash collision

    (Or "hash clash") When two different keys hash
   to the same value, i.e. to the same location in a hash
   table.

   ESR once asked a friend what he expected Berkeley to be
   like.  The friend replied, "Well, I have this mental picture
   of naked women throwing Molotov cocktails, but I think that's
   just a collision in my hash tables."

   [Jargon File]

   (1995-01-23)