Chiefly British Slang
1. Aggressive or violent behavior.
2. Irritation or exasperation: "Postponing new hospitals and roads causes far less aggro than sacking town hall or Whitehall workers" (Economist).
1. Aggressive or violent.
2. Daring and skillful, especially in a sport such as surfing.
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.