Antonyms of noun sister

1 of 4 senses of sister

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

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

4 senses of sister

Sense 1
sister, sis -- (a female person who has the same parents as another person; "my sister married a musician")
       => female sibling -- (a person's sister)

Sense 2
Sister -- ((Roman Catholic Church) a title given to a nun (and used as a form of address); "the Sisters taught her to love God")
       => nun -- (a woman religious)

Sense 3
sister -- (a female person who is a fellow member of a sorority or labor union or other group; "none of her sisters would betray her")
       => 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 4
baby, babe, sister -- ((slang) sometimes used as a term of address for attractive young women)
       => girl, miss, missy, young lady, young woman, fille -- (a young woman; "a young lady of 18")