Source : Webster's Revised Unabridged Dictionary (1913)

      An ugly serpent which forestalled their way. --Fairfax.

      But evermore those damsels did forestall Their furious
      encounter.                                  --Spenser.

      To be forestalled ere we come to fall.      --Shak.

      Habit is a forestalled and obstinate judge. --Rush.

   3. To deprive; -- with of. [R.]

            All the better; may This night forestall him of the
            coming day!                           --Shak.

   4. (Eng. Law) To obstruct or stop up, as a way; to stop the
      passage of on highway; to intercept on the road, as goods
      on the way to market.

   {To forestall the market}, to buy or contract for merchandise
      or provision on its way to market, with the intention of
      selling it again at a higher price; to dissuade persons
      from bringing their goods or provisions there; or to
      persuade them to enhance the price when there. This was an
      offense at law in England until 1844. --Burrill.

   Syn: To anticipate; monopolize; engross.