A1
a man or boy with the same parents as another person:
Do you have any brothers and sisters?
I have three brothers and a sister.
Johnny is my younger/older/big/baby/little brother.
My brother lives in Washington.
a man who is a member of the same group as you or who shares an interest with you or has a similar way of thinking to you:
[ as form of address ] "Let us unite, brothers and fight this unjust law!"
sometimes used by a black man to address or refer to another black man
used as the title of a man, such as a monk, who belongs to a religious organization:
Brother Michael and Brother John were deep in conversation.
[ as form of address ] Bless you, Brother.