Definitions
1.nounSon of the same parents as another person.
2.nounA male having at least one parent in common with another (see half-brother, stepbrother).
3.nounA male fellow member of a religious community, church, trades union etc."I would like to thank the brother who just spoke."
4.nounA form of address to a man."Listen, brother, I don't know what you want, but I'm not interested."
5.nounA black male.
6.nounSomebody, usually male, connected by a common cause or situation.
7.nounSomeone who is a peer, whether male or female.
8.verbTo treat as a brother.
9.interjectionExpressing exasperation."We're being forced to work overtime? Oh, brother!"