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 ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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