Source : Webster's Revised Unabridged Dictionary (1913)

Chad \Chad\, n.
   See {Shad}. [Obs.]

Source : WordNet®

chad
     n 1: a small piece of paper that is supposed to be removed when a
          hole is punched in a card or paper tape
     2: a lake in north central Africa; fed by the Shari river [syn:
         {Lake Chad}]
     3: a landlocked desert republic in north-central Africa; was
        under French control until 1960 [syn: {Republic of Chad},
        {Tchad}]
     4: a family of Afroasiatic tonal languages (mostly two tones)
        spoken in the regions west and south of Lake Chad in north
        central Africa [syn: {Chadic}, {Chadic language}]

Source : Free On-Line Dictionary of Computing

chad
     
         /chad/ (Or "selvage" /sel'v*j/ (sewing and
        weaving), "{perf}", "perfory", "snaf").  1. The perforated
        edge strips on paper for {sprocket feed} printers, after they
        have been separated from the printed portion.
     
        The term {perf} may also refer to the perforations themselves,
        rather than the chad they produce when torn.
     
        [Why "snaf"?]
     
        2. (Or "chaff", "computer confetti", "keypunch droppings") The
        confetti-like bits punched out of {punched cards} or {paper
        tape} which collected in the {chad box}.
     
        One of the {Jargon File}'s correspondents believed that "chad"
        derived from the {chadless keypunch}.
     
        [{Jargon File}]
     
        (1997-07-18)