preempt

Short definition from Wiktionary

Verb

1. 1
   To appropriate first.
2. 2
   To displace or take the place of (by having higher precedence, etc).
3. 3
   To prevent or beat to the punch, to forestall an expected occurrence by acting first.
4. 4
   To secure (land, etc.) by the right of preemption (purchasing before others, e.g. land because one already occupies it).
5. 5
   To make a preemptive bid at bridge.

Noun

1. 1
   A preemptive bid.