A male sibling
sibling, male sibling, stepbrother, half brother, foster brother, kinsman, blood relative, sib, big brother, kid brother*, bro*; see also relative.
A fellow member of a group
associate, colleague, confrere, compatriot, fellow member, fellow human being, fellow creature, fellow man, soul brother, blood brother, buddy*; see also associate, friar.
"brother." YourDictionary, n.d. Web. 16 August 2018. <http://thesaurus.yourdictionary.com/brother>.
brother. (n.d.). Retrieved August 16th, 2018, from http://thesaurus.yourdictionary.com/brother
A person whom one knows well, likes, and trusts: