Definition of preempt | Bee Dictionary of English

n a high bid that is intended to prevent the opposing players from bidding
v acquire for oneself before others can do so
v take the place of or have precedence over
live broadcast of the presidential debate preempts the regular news hour
discussion of the emergency situation will preempt the lecture by the professor
v gain possession of by prior right or opportunity, especially so as to obtain the right to buy (land)
v make a preemptive bid in the game of bridge

Activists point out that the clampdown may well be provoking the backlash it aimed to preempt.
The Minister did not want to preempt the announcement in the Parliament and therefore evaded the question very skillfully.
One day before the televised debate, the Senator tried to preempt the coming criticism.

Oregon LNG goes for federal license, says approval would override county opposition
Supporters say federal approval of the project, including its feeder pipeline, would preempt local authorities withdrawal of land use approvals for the pipeline.
June 12, 2013 - The Oregonian
West Coast senators try to preempt Pebble Mine in Alaska
Senators from Washington, Oregon and California, in a letter to President Obama, are seeking to preempt a huge proposed mining project in Alaska that would be located between two prime salmon spawning streams of North America’s premier commercial and sport salmon fishery. “The Pebble Mine would be one of the largest hard rock mines Read More
June 10, 2013 - seattlepi.com
Bill to preempt local labor laws reaches gov's desk
A bill that may serve as a litmus test on Gov. Rick Scott's view of government reached his desk today, giving the governor 15 days to decide whether to sign or reject HB 655, which preempts local control over issues such as "sick time" and wages and replaces it with regulation from Tallahassee.
June 10, 2013 - St. Petersburg Times Blogs

Hillary Rodham Clinton in CCTV
Hillary Clinton said, "I am very hopeful that we will see a resolution in line with the constitutional order in the next several days, but I don't want to preempt in any way President Karzai's statement which will set the stage for how we go forward...
Duncan Hunter in CNN International
I would authorize the use of tactical nuclear weapons if there was no other way to preempt those particular centrifuges,Hunter said.
Mark Cuban in ESPN
As bad as the allegations facing the NBA today are, its also an opportunity to face every allegation that has ever been directed towards the NBA and its officials and preempt them from ever occurring in the future,Cuban wrote in a message...