The origin of the term chad is uncertain. Patent documents from the 1930s and 1940s show the word "chad", often in reference to punched tape used in
telegraphy. These patents sometimes include synonyms such as "
chaff" and "
chips". A patent filing in 1930 included a "receptacle or
chad box ... to receive the chips cut from the edge of the tape." A 1938 patent filing included a "chaff or
chad chute" to collect the waste fragments. Both patents were assigned to
Teletype Corporation. The plural
chads is attested from about 1939, along with
chadless, meaning "without [loose] chad". Clear definitions for both terms are offered by Walter Bacon in a patent application filed in 1940 assigned to
Bell Telephone Laboratories: "... In making these perforations, the perforator cuts small round pieces of paper, known in the art as
chads, out of the tape. These
chads are objectionable ...
Chadless tape is prepared by feeding blank tape through a device which will not punch a complete circle in the tape but, instead, will only cut approximately three-quarters of the circumference of a circle ... thereby leaving a movable, or hinged, lid of paper in the tape." In the ''
New Hacker's Dictionary, two unattributed and likely humorous derivations for "chad" are offered, a back-formation from a personal name "Chadless" and an acronym for "Card Hole Aggregate Debris". Other etymologies claim derivation from the Scottish name for river gravel, chad, or the British slang for louse, chat''. ==Partially punched chad==