1. An older brother.
2. A man who assumes the role of an older brother, as by providing guidance or protection.
a. also Big Brother An omnipresent, seemingly benevolent figure representing the oppressive control over individual lives exerted by an authoritarian government.
b. A state, organization, or leader regarded in this manner.
[Sense 3, after Big Brother, a character in the novel 1984 by George Orwell.]
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.