Antonyms of noun brother

1 of 5 senses of brother

Sense 1
brother, blood brother -- (a male with the same parents as someone else; "my brother still lives with our parents")
       Antonym of sister (Sense 1)
      => sister, sis -- (a female person who has the same parents as another person; "my sister married a musician")

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun brother

5 senses of brother

Sense 1
brother, blood brother -- (a male with the same parents as someone else; "my brother still lives with our parents")
       => male sibling -- (a sibling who is male)

Sense 2
brother -- (a male person who is a fellow member (of a fraternity or religion or other group); "none of his brothers would betray him")
       => member, fellow member -- (one of the persons who compose a social group (especially individuals who have joined and participate in a group organization); "only members will be admitted"; "a member of the faculty"; "she was introduced to all the members of his family")

Sense 3
buddy, brother, chum, crony, pal, sidekick -- (a close friend who accompanies his buddies in their activities)
       => friend -- (a person you know well and regard with affection and trust; "he was my best friend at the university")

Sense 4
brother, comrade -- (used as a term of address for those male persons engaged in the same movement; "Greetings, comrade!")
       => friend -- (a person you know well and regard with affection and trust; "he was my best friend at the university")

Sense 5
Brother -- ((Roman Catholic Church) a title given to a monk and used as form of address; "a Benedictine Brother")
       => monk, monastic -- (a male religious living in a cloister and devoting himself to contemplation and prayer and work)