Not tolerant, especially:
a. Unwilling to tolerate differences in opinions, practices, or beliefs, especially religious beliefs.
b. Opposed to the inclusion or participation of those different from oneself, especially those of a different racial, ethnic, or social background.
c. Unable or unwilling to endure or support: intolerant of interruptions; a community intolerant of crime.
d. Unable to digest or metabolize a food, drug, or other substance or compound: people who are lactose intolerant.
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.