Top definition
Sonssib = Son's sib(ling). Your son's half brother or half sister, therefore not your birthchild. Also, not your adopted child or stepchild. Likely a child your ex had after you were apart. Usually only used in writing, and in plural form.
Yesterday I saw my sonssibs at my son's party.
by Dr. Phil Collins June 16, 2006
Get the mug
Get a Sonssib mug for your sister-in-law Beatrix.