The Collaborative International Dictionary of English v.0.48:

Sophistry \Soph"ist*ry\, n. [OE. sophistrie, OF. sophisterie.]
   1. The art or process of reasoning; logic. [Obs.]
      [1913 Webster]

   2. The practice of a sophist; fallacious reasoning; reasoning
      sound in appearance only.
      [1913 Webster]

            The juggle of sophistry consists, for the most part,
            in usig a word in one sense in the premise, and in
            another sense in the conclusion.      --Coleridge.
      [1913 Webster]

   Syn: See Fallacy.
        [1913 Webster]

WordNet (r) 3.0 (2006):

sophistry
    n 1: a deliberately invalid argument displaying ingenuity in
         reasoning in the hope of deceiving someone [syn: sophism,
         sophistry, sophistication]

The Devil's Dictionary (1881-1906):

SOPHISTRY, n.  The controversial method of an opponent, distinguished
from one's own by superior insincerity and fooling.  This method is
that of the later Sophists, a Grecian sect of philosophers who began
by teaching wisdom, prudence, science, art and, in brief, whatever men
ought to know, but lost themselves in a maze of quibbles and a fog of
words.

    His bad opponent's "facts" he sweeps away,
    And drags his sophistry to light of day;
    Then swears they're pushed to madness who resort
    To falsehood of so desperate a sort.
    Not so; like sods upon a dead man's breast,
    He lies most lightly who the least is pressed.
                                                        Polydore Smith