The Collaborative International Dictionary of English v.0.48:

-dom \-dom\
   A suffix denoting:
   (a) Jurisdiction or property and jurisdiction, dominion, as
       in kingdom earldom.
   (b) State, condition, or quality of being, as in wisdom,
       freedom.

   Note: It is from the same root as doom meaning authority and
         judgment. ?. See Doom.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dom \Dom\ (d[o^]m), n. [Pg. See Don.]
   1. A title anciently given to the pope, and later to other
      church dignitaries and to some monastic orders. See Don,
      and Dan.
      [1913 Webster]

   2. In Portugal and Brazil, the title given to a member of the
      higher classes.
      [1913 Webster]

The Free On-line Dictionary of Computing (19 January 2023):

Document Object Model
DOM

    A W3C specification
   for application program interfaces for accessing the content
   of HTML and XML documents.

   (http://w3.org/DOM/).

   (1999-12-14)