preemptive

pre·emp·tive

adjective \-ˈem(p)-tiv\

: done to stop an unwanted act by another group, country, etc., from happening

Full Definition of PREEMPTIVE

1

a :  of or relating to preemption

b :  having power to preempt

2

of a bid in bridge :  higher than necessary and intended to shut out bids by the opponents

3

:  giving a stockholder first option to purchase new stock in an amount proportionate to his existing holdings

4

:  marked by the seizing of the initiative :  initiated by oneself <a preemptive attack>

— pre·emp·tive·ly adverb

Examples of PREEMPTIVE

1. The country took preemptive action against the perceived enemy.
2. a preemptive attack by the army

First Known Use of PREEMPTIVE

1855