The Collaborative International Dictionary of English v.0.48:

deckle \dec"kle\ (d[e^]k"k'l), n. [Cf. G. deckel cover, lid.]
   (Paper Making)
   A separate thin wooden frame used to form the border of a
   hand mold, or a curb of India rubber or other material which
   rests on, and forms the edge of, the mold in a paper machine
   and determines the width of the paper. [Spelt also deckel,
   and dekle.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

deckle
    n 1: rough edge left by a deckle on handmade paper or produced
         artificially on machine-made paper [syn: deckle edge,
         deckle]
    2: (paper making) a frame used to form paper pulp into sheets

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

deckle
 /dek'l/, n.

    [from dec- and nybble; the original spelling seems to have been decle]
    Two nickles; 10 bits. Reported among developers for Mattel's GI 1600 (the
    Intellivision games processor), a chip with 16-bit-wide RAM but 10-bit-wide
    ROM. See nybble for other such terms.


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

deckle

   /dek'l/ (From "dec-" and "nibble"; the original spelling
   seems to have been "decle") Two nickles; 10 bits.
   Reported among developers for Mattel's GI 1600 (the
   Intellivision games processor), a chip with 16-bit wide
   RAM but 10-bit wide ROM.

   [Jargon File]

   (1994-11-23)