1. Used as a courtesy title before the surname, full name, or professional title of a man, usually written in its abbreviated form: Mr. Jones; Mr. Secretary.
2. Used as the official term of address for certain US military personnel, such as warrant officers.
3. mister Informal Used as a form of address for a man: Watch your step, mister.
4. Informal One's husband or boyfriend: My mister says hello.
[Alteration of MASTER.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.