The Collaborative International Dictionary of English v.0.48:

Foreclose \Fore*close"\, v. t. [imp. & p. p. Foreclosed; p.
   pr. & vb. n. Foreclosing.] [F. forclos, p. p. of forclore
   to exclude; OF. fors, F. hors, except, outside (fr. L. foris
   outside) + F. clore to close. See Foreign, and Close, v.
   t.]
   To shut up or out; to preclude; to stop; to prevent; to bar;
   to exclude.
   [1913 Webster]

         The embargo with Spain foreclosed this trade. --Carew.
   [1913 Webster]

   To foreclose a mortgager (Law), to cut him off by a
      judgment of court from the power of redeeming the
      mortgaged premises, termed his equity of redemption.

   To foreclose a mortgage, (not technically correct, but
      often used to signify) the obtaining a judgment for the
      payment of an overdue mortgage, and the exposure of the
      mortgaged property to sale to meet the mortgage debt.
      --Wharton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

foreclose
    v 1: keep from happening or arising; make impossible; "My sense
         of tact forbids an honest answer"; "Your role in the
         projects precludes your involvement in the competitive
         project" [syn: prevent, forestall, foreclose,
         preclude, forbid]
    2: subject to foreclosing procedures; take away the right of
       mortgagors to redeem their mortgage