Quash

v. suppress, quell, put down forcibly; invalidate, annul

Verb
1. put down by force or intimidation; "The government quashes any attempt of an uprising"; "China keeps down her dissidents very efficiently"; "The rich landowners subjugated the peasants working the land"
(synonym) repress, keep down, subdue, subjugate, reduce
(hypernym) oppress, suppress, crush
2. declare invalid; "The contract was annulled"; "void a plea"
(synonym) invalidate, annul, void, avoid, nullify
(hypernym) cancel, strike down
(hyponym) break

(v. t.)
To crush; to subdue; to suppress or extinguish summarily and completely; as, to quash a rebellion.
  

(v. t.)
To beat down, or beat in pieces; to dash forcibly; to crush.
  

(v. t.)
To abate, annul, overthrow, or make void; as, to quash an indictment.
  

(v. i.)
To be shaken, or dashed about, with noise.
  

(n.)
Same as Squash.
  

To set aside. - (read more on Quash)