WordNet (r) 3.0 (2006):

DD
    n 1: a doctor's degree in religion [syn: Doctor of Divinity,
         DD]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

DD
       Data Dictionary (SA, CASE, DB)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

DD
       Depacketization Delay


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

DD
       Dansk Dataforening (org., Denmark)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

DD
       Double Density [disks] (FDD)


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

dd
 /dee?dee/, vt.

    [Unix: from IBM JCL] Equivalent to cat or BLT. Originally the name of
    a Unix copy command with special options suitable for block-oriented
    devices; it was often used in heavy-handed system maintenance, as in ?Let's
    dd the root partition onto a tape, then use the boot PROM to load it back
    on to a new disk?. The Unix dd(1) was designed with a weird, distinctly
    non-Unixy keyword option syntax reminiscent of IBM System/360 JCL (which
    had an elaborate DD ?Dataset Definition? specification for I/O devices);
    though the command filled a need, the interface design was clearly a prank.
    The jargon usage is now very rare outside Unix sites and now nearly
    obsolete even there, as dd(1) has been deprecated for a long time (though
    it has no exact replacement). The term has been displaced by BLT or
    simple English ?copy?.


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

DD

   1.  double density.

   2.  data dictionary.

   3.  Deployment Descriptor.

   (2005-01-26)


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

dd

   A Unix copy command with special options suitable for
   block-oriented devices; it was often used in heavy-handed
   system maintenance, as in "Let's "dd" the root partition
   onto a tape, then use the boot PROM to load it back on to a
   new disk".

   dd had a distinctly non-Unixy keyword option syntax
   reminiscent of IBM System/360 JCL (which had an elaborate
   DD "Dataset Definition" specification for I/O devices).
   Though the command filled a need, the interface design was
   clearly a prank.

   [Jargon File]

   (2005-08-08)