brother

Noun

• (Roman Catholic Church) a title given to a monk and used as form of address
  • a Benedictine Brother
    

• used as a term of address for those male persons engaged in the same movement
  • Greetings, comrade!
    

• a close friend who accompanies his buddies in their activities

• a male person who is a fellow member (of a fraternity or religion or other group)
  • none of his brothers would betray him
    

• a male with the same parents as someone else
  • my brother still lives with our parents
    

Related words

• Synonyms: 
  Brother , comrade , buddy , chum , crony , pal , sidekick , blood brother
• Antonyms: 
  sister , sis