intr.v. dis·a·greed, dis·a·gree·ing, dis·a·grees
a. To have a differing opinion: She disagrees with him on everything. They say it will rain, but I disagree.
b. To dispute or quarrel: When those two disagree, there is a lot of yelling.
2. To fail to correspond: Our figures disagree.
3. To cause adverse effects: Caffeine disagrees with me.
[Middle English disagreen, from Old French desagreer : des-, dis- + agreer, to agree; see AGREE.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.