<p><strong>Noun</strong></p><ul><li>a male offspring having both parents in common with another offspring; a male sibling.</li><li>a male offspring having only one parent in common with another offspring.</li><li>a stepbrother.</li><li>a male numbered among the same kinship group, nationality, ethnicity, profession, etc., as another; an associate; a fellow member, fellow countryman, fellow man, etc.: a fraternity brother.</li><li>a male numbered among the lay members of a religious organization that has a priesthood.</li><li>a man who devotes himself to the duties of a religious order without taking holy orders, or while preparing for holy orders.</li><li>brothers, all members of a particular racial or ethnic group, or of the human race in general: All men are brothers.</li><li>slang, fellow; buddy: Brother, can you spare a dime?</li><li>informal, a term used to refer to or address a fellow Black man; soul brother.</li></ul><p><strong>Interjection</strong></p><ul><li>slang (used to express disappointment, disgust, or surprise).</li></ul>