Main Entry: pre·empt
Pronunciation: prE-'em(p)t
Function: verb
Etymology: back-formation from preemption
transitive verb
1 : to acquire (as land) by preemption
2 : to seize upon to the exclusion of others : take for oneself <the movement was then preempted by a lunatic fringe>
3 : to replace with something considered to be of greater value or priority : take precedence over <the program did not appear, having been preempted by a baseball game -- Robert MacNeil>
4 : to gain a commanding or preeminent place in
5 : to prevent from happening or taking place : FORESTALL, PRECLUDE