pre-emptive

1.先发制人的done to stop sb taking action, especially action that will be harmful to yourself

1.(桥牌中叫牌,战争等)先发制人的

2.先买的,有先买权的

1.done before somebody else has had an opportunity to act so as to make his or her planned action pointless or impossible

2.intended to eliminate or lessen an enemy's capacity to attack

3.in bridge, intended to prevent further bidding

4.done or said to prevent something from happening