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definitions

birth family

noun
  1. one's biological parents and siblings, as contrasted with one's adoptive family.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
birth family in Medicine

birth family

n.
  1. A family consisting of one's biological as opposed to adoptive parents and their offspring.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.