A brother by blood: a brother-german or half-brother, as distinguished from step-brothers.
An unrelated male considered to share such a strong relationship generally.
An unrelated male considered to share a brother-like relationship established by a ceremonial sharing of blood in some cultures.
brother (a male sibling)
fratboy (or someone that espouses the fraternity bro culture)
brother (a male comrade or friend; one who shares one’s ideals)
brother (usually used to address a male)
he or him