WordNet (r) 3.0 (2006):

punch card
    n 1: a card on which data can be recorded in the form of punched
         holes [syn: punched card, punch card, Hollerith card]

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

punched card
punch card

    (Or "punch card") The signature medium of
   computing's Stone Age, now long obsolete outside of a few
   legacy systems.  The punched card actually predates
   computers considerably, originating in 1801 as a control
   device for Jacquard looms.  Charles Babbage used them as a
   data and program storage medium for his Analytical Engine:

   "To those who are acquainted with the principles of the
   Jacquard loom, and who are also familiar with analytical
   formulæ, a general idea of the means by which the Engine
   executes its operations may be obtained without much
   difficulty.  In the Exhibition of 1862 there were many
   splendid examples of such looms. [...] These patterns are then
   sent to a peculiar artist, who, by means of a certain machine,
   punches holes in a set of pasteboard cards in such a manner
   that when those cards are placed in a Jacquard loom, it will
   then weave upon its produce the exact pattern designed by the
   artist.  [...]  The analogy of the Analytical Engine with this
   well-known process is nearly perfect.  There are therefore two
   sets of cards, the first to direct the nature of the
   operations to be performed -- these are called operation
   cards: the other to direct the particular variables on which
   those cards are required to operate -- these latter are called
   variable cards.  Now the symbol of each variable or constant,
   is placed at the top of a column capable of containing any
   required number of digits."

   -- from Chapter 8 of Charles Babbage's "Passages from the Life
   of a Philosopher", 1864.

   The version patented by Herman Hollerith and used with
   mechanical tabulating machines in the 1890 US Census was a
   piece of cardboard about 90 mm by 215 mm.  There is a
   widespread myth that it was designed to fit in the currency
   trays used for that era's larger dollar bills, but recent
   investigations have falsified this.

   IBM (which originated as a tabulating-machine manufacturer)
   married the punched card to computers, encoding binary
   information as patterns of small rectangular holes; one
   character per column, 80 columns per card.  Other coding
   schemes, sizes of card, and hole shapes were tried at various
   times.

   The 80-column width of most character terminals is a legacy of
   the IBM punched card; so is the size of the quick-reference
   cards distributed with many varieties of computers even today.

   See chad, chad box, eighty-column mind, green card,
   dusty deck, lace card, card walloper.

   [Jargon File]

   (1998-10-19)