forestall

Short definition from Wiktionary

Verb

1. 1
   To prevent, delay or hinder something by taking precautionary or anticipatory measures; to avert.
2. 2
   To preclude or bar from happening, render impossible.
3. 3
   To purchase the complete supply of a good, particularly foodstuffs, in order to charge a monopoly price.
4. 4
   To anticipate, to act foreseeingly.
5. 5
   To deprive (with of).
6. 6
   To obstruct or stop up, as a road; to stop the passage of a highway; to intercept on the road, as goods on the way to market.

Noun

1. 1
   An ambush; plot; an interception; waylaying; rescue.
2. 2
   Something situated or placed in front.