sib

²sib

noun

Definition of SIB

1

a : kindred, relatives b : a blood relation : kinsman

2

: a brother or sister considered irrespective of sex; broadly : any plant or animal of a group sharing a degree of genetic relationship corresponding to that of human sibs

3

: a group of persons unilaterally descended from a real or supposed ancestor

First Known Use of SIB

before 12th century