a. Undertaken or intended to deter or prevent an anticipated, usually unpleasant situation or occurrence: The two companies organized a preemptive alliance against a possible takeover by another firm.
b. Having the power to preempt or take precedence: preemptive authority.
2. Games Relating to or being a bid in bridge at a high level that is intended to interfere with the opponents' bidding.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.