The Collaborative International Dictionary of English v.0.48:

clogged \clogged\ adj.
   1. obstructed so as to prevent or hinder flow of a fluid; --
      of conduits; as, clogged pipes; clogged arteries.

   Syn: choked.
        [WordNet 1.5]

   2. filled beyond capacity (with people or vehicles), so as to
      retard movement; as, The store aisles were clogged with
      shoppers on the day before Christmas.; The clogged
      highways made me miss my appointment..

   Syn: choked.
        [PJC]

The Collaborative International Dictionary of English v.0.48:

Clog \Clog\, v. t. [imp. & p. p. Clogged (kl[o^]gd); p. pr. &
   vb. n. Clogging.]
   1. To encumber or load, especially with something that
      impedes motion; to hamper.
      [1913 Webster]

            The winds of birds were clogged with ace and snow.
                                                  --Dryden.
      [1913 Webster]

   2. To obstruct so as to hinder motion in or through; to choke
      up; as, to clog a tube or a channel.
      [1913 Webster]

   3. To burden; to trammel; to embarrass; to perplex.
      [1913 Webster]

            The commodities are clogged with impositions.
                                                  --Addison.
      [1913 Webster]

            You 'll rue the time
            That clogs me with this answer.       --Shak.

   Syn: Impede; hinder; obstruct; embarrass; burden; restrain;
        restrict.
        [1913 Webster]

WordNet (r) 3.0 (2006):

clogged
    adj 1: thickened or coalesced in soft thick lumps (such as clogs
           or clots); "clotted blood"; "seeds clogged together"
           [syn: clogged, clotted]
    2: stopped up; clogged up; "clogged pipes"; "clogged up
       freeways"; "streets choked with traffic" [syn: choked,
       clogged]
    3: loaded with something that hinders motion; "The wings of
       birds were clogged with ice and snow"-Dryden