[1] : The Collaborative International Dictionary of English v.0.48

preclude \preclude"\, v. t. imp.  p. p. precluded; p. pr. 
   vb. n. precluding. l. praecludere, praeclusum; prae
   before + claudere to shut. see close, v.
   1. to put a barrier before; hence, to shut out; to hinder; to
      stop; to impede.
      1913 webster

            the valves preclude the blood from entering the
            veins.                                --e. darwin.
      1913 webster

   2. to shut out by anticipative action; to prevent or hinder
      by necessary consequence or implication; to deter action
      of, access to, employment of, etc.; to render ineffectual;
      to obviate by anticipation.
      1913 webster

            this much will obviate and preclude the objections.
                                                  --bentley.
      1913 webster
see also:
precluded precluding close 

[2] : WordNet (r) 2.0

preclude
     v 1: keep from happening or arising; have the effect of
          preventing; "my sense of tact forbids an honest answer"
          syn: prevent, forestall, foreclose, forbid
     2: make impossible, especially beforehand syn: rule out, close
        out
see also:
prevent forestall foreclose forbid rule out close out 

[3] : Moby Thesaurus II by Grady Ward, 1.0

73 moby thesaurus words for "preclude":
   anticipate, avert, avoid, ban, bar, bar out, block, blockade,
   cease, check, count out, cut off, debar, deflect, deny, deter,
   disallow, discontinue, discourage, dishearten, embargo, enjoin,
   estop, exclude, exclude from, fend, fend off, forbid, foreclose,
   forestall, freeze out, frustrate, help, hinder, ignore, impede,
   inhibit, interdict, interfere with, keep from, keep off, keep out,
   leave out, lock out, obstruct, obviate, omit, ostracize, outlaw,
   pass over, prevent, prohibit, proscribe, quit, refuse, reject,
   relegate, repel, repress, repudiate, rule out, save, say no to,
   send to coventry, shut out, stave off, stop, suppress, taboo,
   thwart, turn aside, ward, ward off

Preclude >> P Words
Preclude, definition of term: Preclude
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