stepfamily

noun

1. Any family having one or more stepchildren or stepparents.

   “Researchers are finding that the incidence of violence and abuse is vastly greater in stepfamilies than in traditional families in which the children are biologically related to both parents and to one other.”

   “Meanwhile, thanks to the huge number of second marriages, a third of all Americans are part of a stepfamily.”

2. The family of one's stepfather or stepmother; those immediate family members not related by blood.