/ ˈbrʌðə(r); NAmE / noun , exclamation
■ noun
IN FAMILY
1.
a boy or man who has the same mother and father as another person :
We're brothers.
He's my brother.
an older / younger brother
a twin brother
Does she have any brothers and sisters ?
Edward was the youngest of the Kennedy brothers.
He was like a brother to me (= very close) .
—see also half-brother , stepbrother
OTHER MEN
2.
( pl. brothers or old-fashioned brethren ) used for talking to or talking about other male members of an organization or other men who have the same ideas, purpose, etc. as yourself :
We must work together, brothers!
He was greatly respected by his brother officers.
We must support our weaker brethren.
IN RELIGIOUS GROUP
3.
(also Brother ) ( pl. brethren or brothers ) a male member of a religious group, especially a monk :
Brother Luke
The Brethren meet regularly for prayer.
FORM OF ADDRESS
4.
( NAmE , informal ) used by black people as a form of address for a black man
AT COLLEGE / UNIVERSITY
5.
(in the US) a member of a fraternity (= a club for a group of male students at a college or university)
■ exclamation
( old-fashioned , especially NAmE ) used to express the fact that you are annoyed or surprised :
Oh brother!
••
WORD ORIGIN
Old English brōthor , of Germanic origin; related to Dutch broeder and German Bruder , from an Indo-European root shared by Latin frater .