pro·hib·i·tive (prō-hĭbĭ-tĭv) also pro·hib·i·to·ry (-tôr′ē)
1. Prohibiting; forbidding: took prohibitive measures.
2. So high or burdensome as to discourage purchase or use: prohibitive prices.
3. So likely to win as to discourage competition: the prohibitive favorite to win the nomination.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.